Wedge dissectors for a medical balloon

ABSTRACT

A cage can be positioned around a medical balloon, such as an angioplasty balloon, to assist in a medical procedure. The cage can include a plurality of strips, each extending between a set of rings including first and second rings. As the balloon expands, the first and second rings move closer together and allow the strips to expand outward. The cage may have wedge dissectors on the strips.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 120 as acontinuation application of U.S. patent application Ser. No. 16/234,422filed on Dec. 27, 2018, which is in turn a continuation of U.S. patentapplication Ser. No. 15/268,407 filed on Sep. 16, 2016, which in turnclaims the benefit under 35 U.S.C. § 119(e) as a nonprovisionalapplication of U.S. Prov. App. No. 62/220,195 filed on Sep. 17, 2015.Each of the foregoing applications are hereby incorporated by referencein its entirety. Any and all applications for which a foreign ordomestic priority claim is identified in the Application Data Sheet asfiled with the present application are hereby incorporated by referenceunder 37 CFR 1.57.

BACKGROUND Field of the Invention

Certain embodiments disclosed herein relate generally to a cage for usewith a medical balloon, such as an angioplasty balloon. Methods ofmanufacturing the cage and treatment methods involving the cage are alsodisclosed, as well as various wedge dissectors and features of splinesthat can be used with the cages. Among other things, the wedgedissectors can be used to create perforations in plaque in a bloodvessel in an effort to control crack propagation and to reduce flowlimiting dissections.

Description of the Related Art

Atherosclerotic occlusive disease is the primary cause of stroke, heartattack, limb loss, and death in the United States and the industrializedworld. Atherosclerotic plaque forms a hard layer along the wall of anartery and is comprised of calcium, cholesterol, compacted thrombus andcellular debris. As the atherosclerotic disease progresses, the bloodsupply intended to pass through a specific blood vessel is diminished oreven prevented by the occlusive process. One of the most widely utilizedmethods of treating clinically significant atherosclerotic plaque isballoon angioplasty.

Balloon angioplasty is a method of opening blocked or narrowed bloodvessels in the body. The balloon angioplasty catheter is placed into theartery from a remote access site that is created either percutaneouslyor through open exposure of the artery. The catheter is passed along theinside of the blood vessel over a wire that guides the way of thecatheter. The portion of the catheter with the balloon attached isplaced at the location of the atherosclerotic plaque that requirestreatment. The balloon is generally inflated to a size that isconsistent with the original diameter of the artery prior to developingocclusive disease.

When the balloon is inflated, the plaque is stretched, compressed,fractured, or broken, depending on its composition, location, and theamount of pressure exerted by the balloon. The plaque is heterogeneousand may be soft in some areas or hard in others causing unpredictablecleavage planes to form under standard balloon angioplasty. Balloonangioplasty can cause plaque disruption and sometimes even arterialinjury at the angioplasty site.

SUMMARY

There is a continuing need to improve the methods for treating occlusivedisease, including balloon angioplasty and other related treatmentsystems. In some embodiments a cage can be positioned around a medicalballoon, such as an angioplasty balloon, to assist in a medicalprocedure. The cage can include at least first and second rings and aplurality of strips. Each strip can extend longitudinally between thefirst and second rings. Moving the cage to an expanded position can movethe first and second rings closer together while expanding the strips.In some examples, the cage may further include spikes on the strips thatcan be used as wedge dissectors to dissect plaque in a vessel, amongother things.

In some embodiments, disclosed herein is a medical balloon catheter, andwedge dissectors and strips that can be configured to be attached to amedical balloon catheter or other expandable member. The ballooncatheter can include any number of the following: an elongate memberhaving an inner lumen, the elongate member defining a longitudinal axis;an expandable balloon connected to the elongate member at a distal endof the elongate member; and a plurality of strips, each strip of theplurality of strips including a plurality of wedge dissectors spacedapart along a surface of each strip, each strip extending longitudinallyalong an outer surface of the balloon. The wedge dissectors can includea strip-facing base surface directly adjacent a surface of each of thestrips and an unhoned radially outward facing surface having a lengthbetween a proximal edge of the radially outward facing surface and adistal edge of the radially outward facing surface and defining a heightof each wedge dissector. The radially outward facing surface has a firstwidth at the proximal edge, a second width smaller than the first widthbetween the proximal edge and the distal edge, and a third width at thedistal edge larger than the second width. In some embodiments, thesecond width corresponds to a single point along the length of theradially outward facing surface. The second width can correspond to acentral segment having a central length in between the proximal edge andthe distal edge. The length of each strip can be less than a length ofthe outer surface of the balloon coaxial to the length of each strip.The length of each strip can also be between about 3% and about 6% lessthan the length of the outer surface of the balloon coaxial to thelength of each strip. The total length of the radially outward facingsurface of each wedge dissector can be less than a total length of thestrip-facing base surface of each wedge dissector. The radially outwardfacing surface can be, for example, one or more curved and/or chamferedsurfaces. The radially outward facing surface can have a first height atthe proximal edge and a second height between the proximal edge and thedistal edge, wherein the second height is greater than the first height.In some cases, a maximal height of the radially outward facing surfaceis at a midpoint between the first unbounded edge and the secondunbounded edge. In some cases, a maximal height of the unbounded surfacecan be offset from a midpoint between the proximal edge and the distaledge. In some embodiments, a lateral surface segment of the wedgedissector from the strip-facing base surface to the proximal edge has afirst segment with a first slope and a second segment with a secondslope different from the first slope. The strip can include a texturedsurface. In some embodiments, the strip can include a plurality of tabson an inferior-facing surface of the strip opposite the wedgedissectors. A plurality of reliefs on the strip can also be included.The strips can in some cases include an elongate length and first andsecond lateral edges. The first and second lateral edges of theplurality of strips can be circumscribed by an adhesive. In someembodiments, a hydrophilic slip layer can surround the outer surface ofthe balloon, the strips, and the wedge dissectors. In some embodiments,at least one polymer retention layer surrounds the outer surface of theballoon, the strips, and the wedge dissectors. The balloon can alsoinclude cones about the lateral ends of the balloon. The cones can havea maximal outer diameter that is greater than about 5% of the maximalouter diameter of the balloon. In some cases, the cones comprise railsoriented with longitudinal axes of the strips.

The cage can be assembled and/or manufactured in many ways, including,in some examples, an extrusion process, material removal from a tube, orby splitting a wire to form the strips.

The cage can assist a medical procedure in many ways. For example, thecage may cover a drug coating on the balloon pre-deployment. In somevariants, when the cage is expanded, the cage may allow access to thedrug coating on the surface of the balloon. In this way, the cage canprevent or reduce the chances that the drug will become diluted duringdelivery or will treat areas of the body not intended for treatment.

As another example, the cage can prevent or reduce dog boning of theballoon by increasing the resistance to expansion of the combinedballoon and cage at the ends of the cage as compared to the center ofthe cage.

In some embodiments, a balloon catheter can comprise an elongate member,a balloon, and a cage. The elongate member can have an inner lumen, theelongate member defining a longitudinal axis. The balloon can beconnected to the elongate member at a distal end of the elongate member.The cage can be for positioning about the balloon. The cage can comprisea plurality of strips and a plurality of rings. The plurality of ringscan be configured to secure the plurality of strips to the ballooncatheter. Each strip of the plurality of strips can have a first ring ofthe plurality of rings at a distal end, a second ring of the pluralityof rings at a proximal end. At least a portion of the strip between thedistal and proximal ends remains uncovered by and/or unconnected to anyring. The balloon and cage are configured to have an initial state andan expanded state, the plurality of strips configured to move with theballoon as it moves toward the expanded state.

According to some embodiments of the balloon catheter, at least some ofthe rings of the plurality of rings comprise a heat shrink material.Further each strip of the plurality of strips can include a plurality ofwedge dissectors spaced along a surface of the strip, each stripextending longitudinally along an outer surface of the balloon. Theplurality of rings can secure the plurality of strips to distal andproximal ends of the balloon. At least some of the strips of theplurality of strips can be secured with rings at intermediate points ofthe balloon. The strip may be secured at intermediate points and/or atthe ends.

In some embodiments, at least some of the rings of the plurality ofrings comprise a part ring having a top layer of heat sink material anda bottom layer, an end of a strip of the plurality of strips sandwichedbetween the top layer and the bottom layer. Some embodiments can includehooks on the strips, grooves on the strips or rings, springs, and otherfeatures.

In some embodiments, a plurality of polyurethane coatings in combinationwith a series of strips collectively produce a cage. In one suchembodiment the cage is comprised as a full or partial single top layeror multiple layers of urethane, polyurethane, or other polymer materialand a bottom layer of urethane, polyurethane, or other polymer material,and a plurality of strips sandwiched between the top layer/s and thebottom layer. Some embodiments can include hooks on the edges of strips,grooves on the strips or rings, springs, and other features.

A method of retrofitting a balloon catheter with a cage can comprise anyof the below steps. Positioning a plurality of strips around an inflatedballoon of a balloon catheter, the strips being positioned equallyspaced around the inflated balloon. Advancing rings of heat shrinkmaterial over the balloon so that each end of the strips of theplurality of strips is covered by a ring heat shrink material. Heatingthe rings of heat shrink material to shrink the rings of heat shrinkmaterial to thereby secure the plurality of strips to the balloon, atleast a portion of each strip of the plurality of strip between distaland proximal ends of the strip remaining uncovered by and/or unconnectedto any ring of heat shrink material.

A method may further include positioning the strips to extend primarilylongitudinally, and/or positioning the strips serially in rows aroundthe balloon with 4 rows, each having between 2-6 strips per row. Thestrips can be attached either permanently or temporarily to the balloonwith an adhesive.

Advancing rings of heat shrink material over the balloon further maycomprise covering a distal end of distal-most strips of the plurality ofstrips with a single ring of heat shrink material. Further, advancingrings of heat shrink material may include covering a proximal end ofproximal-most strips of the plurality of strips with a single ring ofheat shrink material. Still further, it can include covering a proximalend of distal-most strips of the plurality of strips and a distal end ofproximal-most strips with a single ring of heat shrink material.

In some embodiments, a cage can be positioned around an angioplastyballoon. The cage can include first and second rings and a plurality ofstrips. Each strip of the plurality of strips can extend longitudinallybetween the first and second rings. The cage can have a pre-expansionposition and an expanded position, wherein moving to the expandedposition moves the first and second rings closer together whileexpanding the strips.

A method of making a cage for an angioplasty balloon can compriseextruding a plastic tube with a plurality of spaced apart splinespositioned longitudinally along the tube; cutting at least one of thesplines of the plurality of splines to form a plurality of spikespositioned circumferentially around the tube; and cutting the tube toform a plurality of longitudinally extending strips, each stripincluding at least one spike of the plurality of spikes.

A method of making a cage for an angioplasty balloon can comprisesplitting a wire into a plurality of longitudinally extending strips;cutting at least two longitudinally extending strips of the plurality oflongitudinally extending strips to form a plurality of spikes spacedapart along the longitudinally extending strip; and connecting the atleast two longitudinally extending strips to a first ring and a secondring such that each strip of the plurality of longitudinally extendingstrips extends between the first and second rings.

A method of protecting an angioplasty balloon with a drug coating cancomprise providing an angioplasty balloon with a drug coating; providinga cage having a pre-expansion position and an expanded position, thecage comprising: first and second rings; and a plurality of strips, eachstrip of the plurality of strips extending between the first and secondrings; wherein the cage is positioned over the angioplasty balloon suchthat in the pre-expansion position the cage covers the angioplastyballoon radially such that none, or substantially none, of the surfaceof the angioplasty balloon with the drug coating is exposed, and movingto the expanded position moves the first and second rings closertogether while expanding the strips and exposing the angioplasty balloonsurface.

A method of treating a diseased blood vessel can comprise advancing anangioplasty balloon, optionally with a drug coating, to a treatment sitein a diseased blood vessel, the angioplasty balloon having a cagepositioned over the angioplasty balloon, the cage having a pre-expansionposition and an expanded position, the cage comprising: first and secondrings; and a plurality of strips, each strip of the plurality of stripsextending between the first and second rings; expanding the angioplastyballoon at the treatment site, where expanding the angioplasty balloonfurther comprises moving the first and second rings closer togetherwhile expanding the strips, the cage preventing or reducing dog boningof the angioplasty balloon by increasing the resistance to expansion ofthe combined angioplasty balloon and cage at the ends of the cage ascompared to the center of the cage.

In some embodiments, a cage for positioning about an angioplasty ballooncan include a plurality of rings and a plurality of strips. Theplurality of rings can be non-expandable. At least one of the pluralityof rings can be configured to be disposed about a first end of anangioplasty balloon, and at least one of the plurality of rings can beconfigured to be disposed about a second end of the angioplasty balloon.Each of the plurality of strips can include a plurality of protrusionspositioned on the surface of each of the plurality of strips. Each ofthe plurality of rings can be configured to attach to each end of theplurality of strips. The plurality of strips can be attached to theplurality of rings through a coupling. In some embodiments, the cage canhave a first length and a second length. The second length is shorterthan the first length, and the plurality of rings are closer inproximity with each other such that each of the plurality of stripsbends away from each of the plurality of strips.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages are described belowwith reference to the drawings, which are intended to illustrate but notto limit the invention. In the drawings, like reference charactersdenote corresponding features consistently throughout similarembodiments.

FIG. 1A illustrates a cage positioned on an angioplasty balloon in anexpanded position.

FIG. 1B shows an exploded view of an angioplasty balloon that can bepositioned within a cage, both being shown in a pre-expanded position.

FIG. 2 shows a schematic representation of a cage laid flat showing bothlong and short slits.

FIG. 3 shows an angioplasty balloon within a vessel at a treatment sitethat is experiencing dog boning.

FIG. 4A shows an unfinished cage during manufacturing being cut from atube.

FIG. 4B is a cross-section of the unfinished cage of FIG. 4A taken alongline B-B.

FIG. 4C shows the cross-section of FIG. 4B after an additionalmanufacturing step.

FIG. 4D illustrates a cross-section of another embodiment with a largerinterior lumen.

FIG. 4E shows a detail view of a portion of another embodiment of cage.

FIG. 5A shows another embodiment of an unfinished cage duringmanufacturing.

FIG. 5B shows a cross-section of the unfinished cage of FIG. 5A takenalong line B-B.

FIG. 6A shows a wire cut to form strips and wedge dissectors for anembodiment of a cage.

FIG. 6B shows a section of the cut wire of FIG. 6A.

FIG. 7 shows a schematic view of a plurality of strips that areconnected by two rings to form a cage.

FIG. 8 illustrates a two-part ring that can be used to capture strips toform part of a cage.

FIG. 9A is another embodiment of cage with a conical ring.

FIG. 9B is a perspective view of a ring with a tapered outer diameterwherein the ring includes a screw-like feature on its outer surface.

FIG. 10 shows the end of a strip configured to accommodate and besecured by a multi-layer ring to form an end of the cage.

FIG. 11 illustrates another embodiment of the end of a strip configuredto accommodate and be secured by a multi-layer ring to form an end ofthe cage.

FIG. 12 is a perspective view of a ring.

FIG. 13A shows a strip with a hook feature and ring.

FIG. 13B is an end view of strip with a ridged hook feature.

FIG. 13C shows a perspective view of a portion of a cage.

FIG. 13D illustrates a view of a conical distal ring retaining aplurality of strips.

FIGS. 13E-F show a view of one end of a balloon with a cage disposedabout the balloon and the forces applied to the balloon during inflationand deflation.

FIG. 14A illustrates a side view of an embodiment of a cage havingstrips with hooks that can attach to the inside of a balloon neck.

FIG. 14B shows an end view of a cage attached to a balloon asillustrated in FIG. 14A.

FIG. 14C is a cross sectional schematic view of the strip with hooklocked into the balloon neck.

FIG. 14D is an alternative embodiment of the end of a strip with amulti-layer ring to form an end of the cage.

FIG. 14E shows an embodiment of a strip retained by a plurality of ringswith the wedge dissectors protruding from the plurality of rings.

FIG. 15A illustrates a partial view of an embodiment of an angioplastyballoon with an embodiment of a strip bound to the angioplasty balloonwith a plurality of ringed material to form a cage.

FIG. 15B is an angioplasty balloon with a cage having a plurality ofsegmented strips that are bound to the surface of the balloon by aplurality of rings.

FIG. 15C shows an example of the placement of the segmented strips onthe surface of the balloon.

FIG. 15D is another example of the placement of a plurality of segmentedstrips onto the surface of an angioplasty balloon.

FIG. 15E illustrates an example of a plurality of segmented strips boundto the surface of a balloon by a plurality of rings.

FIGS. 16A-C show a plurality of embodiments of strips secured by a ring.

FIG. 17 illustrates a schematic view showing a detail of an embodimentof a cage with a spring.

FIG. 18 illustrates various an embodiments of a cage utilizing aspectsof the spring detail of FIG. 18.

FIG. 19 shows a portion of a cage including a spring strip and spikeconfiguration.

FIG. 20 is a close-up detail view of an embodiment of a wedge dissectoron its associated strip.

FIG. 21 illustrates a schematic perspective view of various dimensionsand terminology of a wedge dissector, according to some embodiments.

FIGS. 21A-G illustrate various embodiments of wedge dissectorgeometries.

FIGS. 22A-22F illustrate respective end and isometric views of variouswedge dissector geometries, according to some embodiments.

FIGS. 23A-23D illustrate respective end and isometric views of variousasymmetric wedge dissector geometries, according to some embodiments.

FIG. 24 illustrates an embodiment illustrating how the unbounded surface204 may have a varying height, according to some embodiments.

FIGS. 25A-25K illustrate various embodiments of strips with reliefs invarious locations.

FIGS. 25L and 25M illustrate embodiments of method of stabilizing stripsduring the laser cutting manufacturing process and involving temporarytabs, according to some embodiments.

FIG. 25N illustrates embodiments of an adhesive ramp for bonding lateralends of a strip to the balloon surface, according to some embodiments.

FIG. 25O illustrates a cone ramp for a balloon, according to someembodiments.

FIG. 25P illustrates a series of cone rails or struts, according to someembodiments.

FIG. 26 illustrate another embodiment of strips having reliefs,according to some embodiments.

FIG. 27 illustrate a schematic cross-section of a balloon with wedgedissector and intervening layers.

FIG. 28 illustrate an embodiment of a pleated balloon with strips andwedge dissectors in between pleats.

DETAILED DESCRIPTION

FIGS. 1A and 1B illustrate an embodiment of a cage 10 positioned on anangioplasty balloon 20. FIG. 1A shows an expanded position and FIG. 1Bshows how the angioplasty balloon can be advanced into the cage. Thecage 10 is described herein primarily with respect to an angioplastyballoon 20 and an angioplasty procedure. It is to be understood that thecage 10 can be used with other types of medical balloons and in otherprocedures.

The cage 10 can include a first ring 12 and second ring 14, and aplurality of strips 16. Each strip can extend longitudinally between thefirst ring 12 and the second ring 14. The strips and rings can be madeof a monolithic part formed from a single piece of material. Thus, thefirst and second rings can be the ends of a cut tube, for example. Thestrips and rings can also be made of separate materials and be connectedtogether. As shown the illustrated cage of FIGS. 1A and 1B has fivestrips 16, though other numbers of strips can be used such as 2, 3, 4,5, 6, 7, 8, 9, 10, etc.

FIG. 2 shows a plan view of a cut tube embodiment of cage, though someembodiments of cage can alternatively be made of a single flat piece ofmaterial. The material can be elastic or semi-elastic and made from apolymer, copolymer, a metal, alloy or combination of these. The stripsare typically designed to enable the balloon 20 to be inflated multipletimes. As well, the strips 16 can be configured such that the cage 10can apply forces both longitudinally and axially or in orientations thatenable the strips 16 to return to this original position.

In some embodiments the cage 10 is prefabricated, packaged, andsterilized separately from the balloon 20, allowing the physician toposition the cage 10 around a medical balloon 20, such as an angioplastyballoon, to assist in a medical procedure at the time of the procedure.FIG. 1B shows the balloon 20 in a folded state prior to deployment andprior to placement within the cage 10. The folded balloon 20 can beadvanced into the cage 10 without requiring expansion or change in shapeof the cage 10. The cage 10 can completely surround and enclose theballoon 20 prior to balloon deployment or expansion. The cage 10 in thepre-expanded state can be longer than the balloon 20. This can allow formovement of one or both ends of the cage 10 towards each other while thedevice (e.g. balloon 20) expands. The cage 10 can be free floating overthe balloon 20. One or both ends 12, 14 of the cage 10 may be fixed tothe balloon 20 or another part of the delivery device. In someembodiments the cage 10 is not attached to any portion of the balloon 20that expands. This can prevent the cage 10 from interfering with theballoon 20 as it expands.

In some examples, a cage 10 can be used with an angioplasty balloon 20with a drug coating to can protect the drug coating. The cage 10 canprevent or reduce the premature exposure of the drug to the bloodvessel. As will be understood with reference to FIG. 1B, the cage 10 canbe positioned over a drug coated angioplasty balloon 20 in thepre-expansion state to prevent premature exposure of the drug to theblood vessel. The cage 10 can cover the balloon 20 radially such that aminimal amount, or substantially none, of the surface of the angioplastyballoon 20 with the drug coating is exposed. The balloon 20 and cage 10can be advanced to a treatment location in this configuration. Thoughnot shown, the system may be advanced over a guidewire within thevasculature.

As illustrated in FIG. 1A, the cage 10 can be moved to an expandedposition. In the expanded position the first 12 and second rings 14 arecloser together and the strips are expanded thereby exposing theangioplasty balloon surface. In this position, the drug can be placedinto contact with diseased tissue in the blood vessel.

In currently available systems, it is generally difficult to predict howmuch drug will reach the diseased tissue. There are many factors thatlimit the ability to accurately predict how much drug will betransferred to the diseased tissue. For example, blood flow can dilutethe drug on the balloon 20 as it is advanced to the treatment site.Furthermore, navigating the device through the blood vessel can causethe balloon 20 to rub against the endoluminal surface thereby removingsome of the drug as the balloon 20 is being advanced to the treatmentlocation. Therefore, in some examples, the cage 10 can offer a physicalbarrier to protect the drug covering of the balloon 20 duringadvancement to the treatment location. In this way the cage 10 can beused such that balloon 20 and drug covering are exposed to blood flow ina vessel only during expansion of the balloon 20 as the space betweenthe strips increases. In this way, the cage 10 can prevent or reduce thechances that the drug will become diluted or that the drug will treatareas of the body that are not meant for treatment. In some variants,this can allow for more controlled delivery of the drug with a reductionin the amount of drug necessary to be coated on the balloon 20.

In some embodiments, the folded balloon 20 can be positioned entirelywithin the cage 10. As is illustrated in FIG. 1A, the cage 10 can haveslits between each of the strips 16. In some variants, the slits can beformed by cutting between each of the strips 16 to separate them from asingle piece of material. In other embodiments, the slits are reallyjust the space between adjacent strips. The space between strips can bea minuscule amount, such as would formed by a laser cut, or much larger,such as equal to or greater than a width of the strip itself. Dependingon the size of the slits, the exposed surface of the balloon 20 in thepre-expansion position is not more than 50% and can be as low as 25%,10%, 5%, 1%, or less.

As has been described previously, expansion of the balloon 20 moves thefirst 12 and second rings 14 closer together while moving the strips 16further apart radially. With the strips 16 in an expanded position, theballoon 20 is more exposed to and can interact with the vessel wall. Inthe expanded position, the balloon 20 can deliver a drug, stem cells, orother treatment to the vessel wall or to a diseased area of the vesselwall. When the balloon 20 is fully expanded, the exposed surface of theballoon 20 not covered by the strips 16 can be between 65% and 99%, 75%and 99%, more commonly 80% and 99%, or most commonly 90% and 99%, amongother ranges.

Drug delivery using the cage 10 can be employed before, during, or afteran angioplasty procedure. At the same time, it is not required that thecage cover the entire balloon, or be used to control or assist with drugdelivery.

In some embodiments, a cage 10 can be used to prevent or reduce dogboning of the balloon 20 in an angioplasty procedure. This may be inaddition to, or instead of assisting with drug delivery. FIG. 3 shows anangioplasty balloon 20 within a blood vessel 2 at a treatment site. Asillustrated, the angioplasty balloon 20 is experiencing dog boning as itis expanding. The plaque buildup 4 resists expansion of the balloon 20,forcing both ends of the balloon 20 to expand first, rather thanfocusing the expansion energy in the center of the balloon 20 at theplaque 4 where it is needed most.

To prevent dog boning, the cage 10 as shown in FIG. 1A, can constrainthe balloon 20 upon expansion to encourage the middle of balloon 20 toexpand first. This is because the middle area of the cage 10 can bedesigned to have the least resistance to expansion, being farthest awayfrom the ends where the strips are confined by rings. This can preventor reduce dog boning of the balloon 20 independent of the diseasemorphology or arterial topography the balloon 20 is expanding within.

Dog boning usually occurs where a balloon 20 expands in a vessel withplaque where the plaque resists expansion, forcing the ends of theballoon 20 to expand first (due to lack of resistance) such that theballoon 20 takes the shape of a dog bone. By enveloping a balloon 20with a cage 10 and configuring the rings to display different expansionresistance, the ends of the balloon 20 can have the highest resistanceand the center of the balloon 20 have the lowest resistance. Therefore,the cage 10 can help control and limit expansion of the balloon 20, asthe balloon 20 will tend to expand more readily in the center which istypically the area of disease.

The pattern and orientation of the strips 16 can influence expansion anddog boning. Returning to FIG. 2, the short slits 22 positioned in thecenter of the strips 16 can reduce rigidity in the center of each of thestrips 16. This can help reduce the likelihood of dog boning by furtherreducing resistance to expansion in the center of the cage 10.

The cage may further include spikes or wedge dissectors on the strips.The spikes can be used as a vessel preparation tool before a secondarytreatment, or during a primary treatment. For example, the spikes canassist with cutting and/or perforating plaque before or during anangioplasty procedure. This may be in addition to, or instead ofassisting with drug delivery and/or preventing dog boning. It will beunderstood that any of the embodiments described herein can provide anyof these benefits and/or be used in any of these procedures, as well asthe other benefits and procedures described herein.

Spikes can be positioned on the strips in any number of differentorientations and configurations as will be described further below. Thespikes can be any of the spikes discussed in U.S. Pat. No. 8,323,243 toSchneider et al., issued Dec. 4, 2012 and incorporated by referenceherein in its entirety. The spikes and cage can also be used inaccordance with the plaque serration methods and other methods alsodescribed therein.

The cage 10 can be made in many ways. For example, an extrusion processmay be used, a tube may be cut, and/or a wire split as will be describedin more detail below. Beginning with FIGS. 4A-5B, various embodiments ofcages will be described. FIGS. 4A and 5A show embodiments of cages 10during the manufacturing process. The cages 10 are each in the form of atube with a plurality of splines 24 spaced apart on the tube. In someembodiments, the tube can be pre-formed and then machined to theillustrated shape. The tube can be made of metal or plastic among othermaterials. In other embodiments, the tube is extruded to form theillustrated shape. For example, a method of making the tube can includeextruding a plastic tube with a plurality of spaced apart splines 24positioned longitudinally along the tube. Cross-sections of the cagesare shown in FIGS. 4B-D and 5A.

After forming the tube with the splines 24, material from the tube canbe removed to form the slits and strips 16. Either as part of removalprocess, or before creating the slits, the splines may be shaped to formdifferent shaped spikes or wedge dissectors 26. For example, the splines24 illustrated in FIG. 4B can be machined to form the sharp wedgedissectors 26 as shown in FIGS. 4C and 4D. In some embodiments, thesplines 24 can be manufactured with an additive process and shapedinitially like the illustrated wedge dissectors 26 without requiringadditional machining or other work.

Looking now to FIG. 4E, an enlarged detail view of a portion of a cageis shown. In this embodiment, the strip 16 has been formed with aplurality of spikes or wedge dissectors 26. In some embodiments, fromthe base of the unfinished cage of FIGS. 4A and 4B, a slit can be cut inthe tube to form adjacent strips. The wedge dissectors 26 can be shapedlike a tent or axe head with an elongated tip and base, both of whichextend longitudinally, along the longitudinal axis of the tube. Thewedge dissectors 26 can assist with cutting and/or perforating plaquebefore or during an angioplasty procedure. The space between the wedgedissectors 26 can be machined or otherwise formed to remove material andincrease the flexibility of the strip. The space between the wedgedissectors 26 is shown as being twice the length of the wedge dissector26, though other spacing can also be used. Typically spacing length canbe 4:1 to 3:1 space to length and more commonly 3:1 to 1:1 space tolength.

Turning to manufacturing of the splines, in some embodiments, thesplines 26 are fabricated from a tube of material, where the cage 10 isa plastic extruded tube with splines that are cut, ground, electricaldischarge machined, or molded to form the wedge dissectors 26. The tubecan be manufactured with slits along its length. In some examples, theends of the tube remain intact in order to forming rings. In somevariants, the strips 16 are spaced apart with some or all the strips 16having spikes or wedge dissectors 26. As will be understood from theabove discussion, in the embodiments shown in FIGS. 4A-5B five slitswould be made to form outward points.

In some embodiments, a method of making a cage 10 for an angioplastyballoon 20 can comprise first extruding a plastic tube with a pluralityof spaced apart splines positioned longitudinally along the tube. Insome examples, the method can then include cutting at least one of thesplines of the plurality of splines to form a plurality of spikes orwedge dissectors 26 positioned circumferentially around the tube. Insome variants, the method can further include cutting the tube to form aplurality of longitudinally extending strips 16, each strip including atleast one spike of the plurality of wedge dissectors 26.

Looking now to FIGS. 6A-6B, another method of manufacturing a cage 10will be described. A wire 28 can be split or cut to form three or morestrips 16 that can be used as part of forming a cage 10. In someexamples, the wire 28 is constructed of an alloy, or polymeric material.Any number of different manufacturing methods can be used includinglaser cutting and electrical discharge machining. In some variants, thewire 28 can be divided into sections, such as four quarters. In someembodiments, square or other shaped holes 30 can be cut into the wire 28to form spaces between the wedge dissectors 26. Each of the sections ofwire can then be separated to form the strips 16 of the cage 10. A cage10 can be assembled with a plurality of rings and include any number ofstrips 16. In some examples, a cage 10 can be assembled from 1, 2, 3, 4,5, 6, 7, 8 or more strips 16.

Systems and Methods for Connecting Individual Strips

Strips 16 can be attached in many ways to form the cage 10. In addition,to forming the strips from a wire, they can also be extruded and/orformed from a flat piece of material and/or a tube. For example, it willbe understood that the embodiments described with reference to FIGS. 2,4A-5B can be modified to provide individual strips that can then beconnected to form a cage.

In some embodiments, strips can be connected with two or more rings 12,14 to form a cage 10. For instance, the individual strips of the cage 10may be bonded to rings on either end. As illustrated in FIG. 7, eachindividual strip 16 is secured on either end by rings 12, 14. Inconstructing the cage 10, the strips 16 can be attached to the rings 12,14 first before positioning around a balloon, or the cage can beassembled around a balloon. For example, one or more strips can beplaced onto the surface of the balloon 20 before connecting to therings. The cage 10 may be permanently fixed to one or both ends of theballoon 20 or to the balloon catheter. In some embodiments, the rings12, 14 can hold the strips against a portion of the balloon or theballoon catheter. The strips 16 can also help to keep the balloon 20 ina compressed state prior to deployment and can assist in deflating theballoon after expansion.

The rings 12, 14 are typically circular bands, though they can be a bandof any number of shapes including oval, square, elliptical, rectangular,etc. The rings can also be capable of producing a binding and/orrestraining force. The rings 12, 14 can be any number of differentmaterials including one or more of a metal, polymer, copolymer,elastomer, thermoplastic elastomer, glue, or hydrogel. The rings can berigid or flexible.

In some examples, the rings 12, 14 can be composed of a heat shrinkmaterial or a material with elastic properties that binds, captures, orrestrains the plurality of strips 16 and prevents or limits the strips16 from moving, sliding, tilting or twisting at any point along thelength of the strips but especially at either end of the balloon 20.When the rings are elastic, super elastic, or thermally active, therings can be placed about the strips and allowed to shrink onto thestrips such that the strips 16 are retained against the outer diameterof the balloon 20. Preferably, the rings and strips are positionedaround a balloon in a fully expanded state and then heat is applied tothe heat shrink type rings. In other embodiments, the heat shrink typesrings are applied with the balloon in a deflated state.

As discussed with respect to FIGS. 1A and 1B the cage can be performedand slid onto the balloon. But, in some embodiments, assembling the cagearound the balloon can allow for a smaller cage design. In retrofittingthe balloon 20, the rings can be advanced onto the balloon catheter fromeither side which may allow for a smaller ring inner dimension ascompared to a cage with one ring that is advanced over a balloon.

The rings 12, 14 of the cage 10 can be configured to accommodate theballoon 20 as it transitions from a deflated to an inflated shape. Notunlike the configuration of the cage with balloon illustrated in FIG.1B, the strips 16 of the cage 10 can be in contact with the balloon 20when the balloon 20 is in a deflated configuration. As the balloon 20inflates, each strip 16 bows in a concave orientation with the balloon20 (FIG. 1A). In some examples, the strips 16 are free-floating and notbound to the balloon surface.

As the balloon 20 begins deflating, the material properties of thestrips 16 can allow it to begin to return to their original position.This may be a completely flat position. As the strips 16 return to theiroriginal position, this can provide an additional force to assist thedeflation of the balloon 20. As the strips move from the concaveposition to a flat linear position, the strips 16 move from an expandedlength (“L_(e)”) to a deflated length (“L_(d)”) where L_(d) is longerthan L_(e). The straightening of the strips 16 from L_(e) to L_(d) inthe axial direction elongates the balloon 20 and assists in morecomplete balloon 20 deflation.

The rings 12, 14 can come in a variety of shapes and sizes that cansecure the plurality of strips 16. The following discussion of certainillustrated embodiments, are but a few such examples.

The rings 12, 14 can connect to the strips 16 in a number of differentways. The rings can be mechanically attached to the strips 16 through afriction fit for example, or can be connected with an ultrasonic weld,adhesive, etc. Turning to FIG. 8, each ring 12, 14 can be a two-partring that can connect to one or more strips 16 of the cage 10 byrotating the rings in opposite directions (e.g. clockwise andcounterclockwise). The rings 12, 14 can include holes 32, through whichthe strips 16 can be advanced to connect to the ring. In particular, theasymmetrical shape of the holes 32 can be configured to accommodate astrip 16 with periodically spaced wedge dissectors 26 such as thatillustrated in FIG. 6B.

As illustrated, the holes 32 can have a narrowed portion 33 and a widerportion 34. The wider portion 34 can be configured to accommodate thewedge dissector 26 while the narrowed portion 33 can be configured toaccommodate the width of the strip 16 (i.e. the space between wedgedissectors). The strips 16 can be advanced through the holes 32 byfitting a wedge dissector 26 through the wider portion 34. In someexamples, the strip 16 can then be secured by turning the rings 12, 14such that the strip 16 is moved into the narrowed portion 33. This cansecure the strips 16 to the rings 12, 14 as the wedge dissector 26cannot move past the narrowed portion 33. As described above, both rings12, 14 can be present at either end of the cage 10. Additionally, asillustrated in FIG. 8, because the holes 32 of the ring 12 and the holes32 of the ring 14 are opposed, by rotating the two parts of the ring inopposite directions, this further prevents movement of the strips 16.

The strips 16 can be secured by rings 12, 14 that are formed from avariety of shapes. For example, FIG. 9A illustrates an embodiment of thecage 10 where the strips 16 are secured with a conical ring 12 at thedistal end. The conical end can be the distal end of the ballooncatheter and can provide an atraumatic end of the device.

Similarly, FIG. 9B shows a ring 12 with a tapered outer diameter with ascrew feature 101 on its outer surface. This screw feature 101 canprovide either a negative or positive impression about the outer surfaceof the distal ring.

The ring 12 illustrated in FIG. 9B can serve a treatment purpose aswell. In some examples, the tapered and screw features on the ring canassist the balloon 20 in navigating and entering a narrow lesion. Thecoiled outer surface 101 can be configured to provide a gripping ortunneling mechanism. This feature can allow the ring to aid the operatorin navigating through occluded lesions (either totally or partially) andenable passage of the balloon 20 therein. The negative or positiveimpression 101 can be circumferential or patterned like a cork screw. Insome embodiments, the negative or positive impression 101 can be macroin scale or have micro features that offer an enhanced surface to enablepassage through a narrowing in a vessel. In some examples, the functionof the outer surface 101 of the ring can be described as acting like alubricant although the feature is mechanical in nature. This functioncan be further enhanced with hydrophilic, hydrophobic coating. Thesurface texture can also be modified to aid in passages with lesspenetration energy. In some embodiments, this can be accomplished byadding micro scales (as seen in porcupine quills) or enhanced surfaceroughness (as used in nature by mosquitos).

The ring 12 illustrated in FIG. 9B can be secured to strips 16 that aredisposed about the surface of the balloon circumferentially in a helicalfashion. In contrast to the linear strips 16 illustrated in FIG. 9A, thestrips 16 attached to the tapered ring 12 can be wound around theballoon. A tapered or untampered ring 14 can be used at the proximal endof the balloon. In some examples, the configuration of the attachedstrips 16 can follow the same pattern as the negative or positiveimpression 101 on the ring 12.

Turning now to FIGS. 10-11, multiple layer rings will be discussed. Aring with multiple layers can be used to hold the strips between thelayers. The ring can have at least a base layer 122 and a top layer 121.As seen in FIGS. 10-11, the ring 12, 14 can have a non-compressiblebottom layer 122 and a compressible, thermally or electrostaticallycompressible layer 121. The top layer 121 can be configured of acompressible material while the base layer 122 can be configured of anon-compressible material and the strips 16 can be captured betweenthem. In some examples, the top layer or the top and base layers can bemade from a heat shrink material. In some embodiments, the ring 12, 14can be formed from lengths of materials that are wound around themselvesto form a layer of ring.

The rings can be made of a layer of composite materials where the baselayer 122 is less compressible or elastic than the top layer 121. Energycan be added to the top layer 121 to produce a reduction in the toplayer's diameter until the top layer compresses and captures the stripsbetween the base layer 122. For example, the top layer 121 can be a heatshrink material. In this way, the top layer 121, base layer 122 andstrips 16 can form a cage 10 as seen in FIGS. 10 and 11. In someembodiments, the strips can be attached to the balloon and/or ballooncatheter with the rings that are made of a single layer of heat shrinkmaterial positioned over the strips similar to just the top layer.

The strips or rings can include indentations to facilitate attachment tothe other. The strip 16 can include an indentation 171 on either side ofthe strip 16 (as illustrated in FIG. 10) or an indentation 171 on onesurface of the strip 16 that can form a groove (as illustrated in FIG.11). Though in FIG. 11, the top layer 121 is shown as a heat shrinkmaterial, it will be understood that in other embodiments a rigid ringcould be press fit into the indentation 171. Such a rigid ring could bepart of a single or multiple layer ring, thus there may or may not be acorresponding base layer 122.

FIG. 12, illustrates another embodiment of the ring 12, 14. Here, thering 12, 14 can include a plurality of indentations or grooves 17. Thegrooves 17 can have a width that can accommodate the width of the distalend of strip 16. An end of a strip can be attached to the ring 12, 14 inthe grooves 17 through the use of adhesive, mechanical coupling,wrapping heat shrink material around the ring, etc. In some embodiments,the strip 16 of FIG. 11 can be placed in the ring 12, 14 of FIG. 12 sothat the indentations are engaged with each other.

FIGS. 13A-C illustrate examples of a strip 16 that includes ansecurement feature 181 that improves the hold of the strips 16 to therings 12, 14. In some variants, the securement feature 181 forms asection of the strip 16 with a higher surface roughness. This can be inthe form of the illustrated ridges or other teeth-like elements that aidin the imbedding of the strip 16 into or holding the strip on the ring.

When the ring 12, 14 is a polymeric material, the securement feature 181can be formed as narrow sections of the strip 16 at the ends (asillustrated in FIG. 13A-B), or placed strategically along the striplength (such as where three or more rings are used). The securementfeature 181 can be aligned with the rings 12, 14. During fabrication,the securement feature 181 can be pressed into the polymeric material asillustrated in FIG. 13A at a high temperature where the polymericmaterial is near or greater than the glass transition temperature of thematerial. In so doing the securement feature 181 can be used to engageor connect the strips 16 to the rings 12, 14 as illustrated in FIG. 13C.

In FIG. 13A the ring 12, 14 is shown to incorporate the securementfeature 181 into the body of the ring material. FIG. 13A shows the strip16 with a ridged hook feature 181 before it is pressed into the ringmaterial. FIG. 13B shows a perspective view of another embodiment ofsecurement feature 181. In some examples, the securement feature 181 canbe significantly longer than the ring 12, 14 is wide and be designed toprovide tension on the cage 10.

When the ring 12, 14 is made from an elastic material, such as rubber orpolymer, or metallic alloy or a design with elastic properties like aspring, the ring 12, 14 can be used to provide tension on the cage 10 toenable the cage 10 to return to the relaxed, deflated balloon 20position. Furthermore, the portion of the strips 16 without a wedgedissector is the thinnest and the most flexible. This can allow thestrip 16 to be the most flexible at the edge of the balloon 20 where theforces are the highest.

FIGS. 13D-F illustrate an example where the elastic material of a ringcan provide tension on a cage during expansion and to then assist indeflating the balloon as the tension is released. Turning first to FIG.13D, the cage 10 is disposed about the balloon 20. The cage 10 can becomposed of a plurality of strips 16 that are secured to the balloon byrings 12, 14. In some examples, the rings 12, 14 can be made from longelastic material that can aid in pulling the strips 16 down into alinear position such that the wedge dissectors are perpendicular to thesurface of the balloon 20. Callout “A” provides a schematic, see-throughview of the proximal end of ring 14. As shown, ring 14 is secured aboutthe outer catheter shaft 22 by an adhesive 23. As well, an innerguidewire shaft 21 can run concentric to the balloon 20. The guidewireshaft 21 can be secured with relationship to the catheter shaft 22. Forexample, the guidewire shaft 21 and the catheter shaft 22 can both beconnected to different ports on a hub, such as the illustratedbifurcated luer at the proximal end of the balloon catheter. The ballooncan be inflated by injecting a fluid into the catheter shaft. It will beunderstood that in some embodiments the catheter shaft 22 open directlyinside the balloon 20, rather than opening at the ring 14 as shown. Thering can be attached to the catheter shaft 22 and/or the balloon 20.

FIGS. 13E-F illustrate a balloon 20 and cage 10 as the balloon 20 isinflated and subsequently deflated. As noted above, in some examples,the elastic material of the rings 12, 14 can stretch to allow the cage10 to expand as the balloon 20 is inflated. In some embodiments such asthe shown in FIGS. 13E-F, the rings can be made of an elastic polymerand the strips can be made of metal or an inelastic polymer. As shown inFIG. 13E, as the balloon 20 is inflated, the strips 16 of the cage 10begin to move apart. In order to push each of the strips 16 outward,force is exerted radially outwards (as illustrated by the arrows) on theballoon 20—and by extension the cage 10—as the balloon 20 is inflated.As the balloon 20 expands, the rings 12, 14 are under tension and ableto stretch enough to allow the strips 16 to maintain alignment whileexpanding with the balloon 20.

This tension can also help the balloon 20 to deflate. During balloondeflation, as illustrated in FIG. 13F, the tension on the strips 16exerts a force radially inward as the strips 16 and the rings 12, 14tend to want to return to a relaxed state. This force pulls on thestrips 16 and allowing them to flatten, thereby providing a narrowedprofile for catheter retraction.

Looking now to FIGS. 14A-D another embodiment of strip 16 is shown withvarious types of rings. As illustrated in FIGS. 14A-B, in some examples,the ring can be fabricated from the lip on the neck of the balloon 20and the portion of the catheter body used to bond the catheter to theballoon 20. The catheter can provide a pathway for gas or liquidinflation of the balloon 20. Additional components such as an over moldor heat shrink can be added to the bond joint, as can additive glue orpolymeric material. In some examples, this can serve to prevent pressurefrom leaking out of the balloon 20 along the length of the strips 16forming the cage 10.

As illustrated in FIGS. 14A-D, a hook 161 at the strip end can enablethe strip to be easily aligned along the balloon surface and can aid inorienting the strip in a longitudinal orientation relative to the axisof the balloon 20. The hook 161 can be integrated into each end of thestrip 16. The hook 161 can be wrapped around the lip of the neck of theballoon 20 from the outer diameter (“OD”) of the balloon 20 neck aroundthe opening and into the neck where the end of the hook 161 rests withinthe inner diameter (“ID”) of the balloon 20 neck.

Both ends of the strip 16 can have a hook 161, or just one end can havethe hook. In addition, the ends can be attached to the balloon catheterin the same or in different ways. For example, heat shrink can bewrapped around the ends of the strips and balloon. In some embodiment,heat shrink is wrapped around one end and a rigid ring, such as thosediscussed with respect to FIGS. 8-12 can be used at the other end, whichmay also include a heat shrink layer.

The strip may or may not be attached to the balloon at other locations.As shown, the strip 16 can also have hinges or pre-bent regions thatcorrespond with the shape of the balloon. Thus, the strip in theexpanded state can have a main portion having wedge dissectors 26 thatis parallel with the axis of the balloon. Angled sections can extendfrom the main portion to the hooks 161. The angled sections can form anangle when the balloon is expanded as shown, but can be flat when theballoon is deflated. In some embodiments, hinges between the sectionscan be formed with thinner sections of material.

As shown in FIG. 14A the strip can attach to the balloon without aseparate ring by use of the hooks 161. The balloon can be glued to acatheter (for example an elongated tube with one or more lumen) whichcan also secure the hook in place. FIG. 14A shows one strip forsimplicity, though it will be understood that 2, 3, 4 (FIG. 14B), 5, ormore strips could be used.

FIG. 14C shows a detail view of the hook 161 attaching to a balloon 20.As can be seen the balloon can serve as a base layer 122 of the ring anda top layer 122 is also shown. Adhesive 123 is also shown securing thetop layer 121 to the balloon. In some embodiments, the top layer 121 canbe the tube of the catheter.

FIG. 14D shows a two layer 121, 122 ring. The two-layer ring can includetwo layers of heat shrink material. As discussed for FIGS. 10-11, thering illustrated in FIG. 14D can be a multi-layer ring where the baselayer 122 is less compressible or elastic than the top layer 121 andwhere energy is added to the top layer producing a reduction in the toplayer's diameter until the top layer compresses and captures the stripsbetween the base layer 122 and the top layer 121 to produce the cage 10.

FIG. 14E illustrates another embodiment of the rings 12, 14 that securethe strips 16 on the surface of the balloon 20. As shown in callout “A,”the rings 12, 14 can be secured to the balloon 20 such that the wedgedissectors protrude through the surface of the rings 12, 14. Callout “A”includes a cut away of the ring 12, 14 in the center in order to showthe strip 16 below. The wedge dissectors can protrude through the rings12, 14 in a variety of ways. For example, the shape of the wedgedissector can cut through the material of the rings 12, 14 as the rings12, 14 are secured to the strips 16. This can form a hole 27. The rings12, 14 can also have a plurality of holes 27 pre-cut into the rings 12,14 to allow the wedge dissectors to extend through.

It can also be seen that the rings 12, 14 can be shaped to correspondwith the taper of the balloon 20. For example, cutouts 29 of material inthe rings can help a ring made of heat shrink material to shrink to theshape of the balloon.

As discussed above, each of the strips 16 can extend between one or tworings, though additional rings can be used as needed. For example,three, four, five, six, seven, eight, nine, or ten, or more rings can beused, especially with longer balloons. As one example, an angioplastyballoon 20 having a length of 300 mm can be fitted with a cage 10 havingtwo rings 12 and 14 at either end. In addition to the rings 12, 14, thecage 10 can include rings 13 or other similar controlling elements thatcan aid the strips 16 in maintaining alignment and orientation as theballoon 20 expands towards the artery wall.

As illustrated in FIG. 15A, the rings 13 can be a fraction of theoverall length of the balloon 20. Some ring 13 designs are less than oneand a half times the length of the balloon 20. In other examples, therings are between 1.0-0.5 times the balloon 20 length. More commonly thelength of the rings 13 are between 2.5 and 1.5 times the balloon 20diameter and typically between 1.5 and 0.5 times the balloon 20diameter. Each ring 12, 13, 14 can be made from a different material soat to provide more than one advantage and function of the rings 12, 13,14.

The rings 13 can be placed on the outer surface of the body of theballoon 20. In some examples, the rings 13 can be designed to retain thebody of the strips 16 such that the position and orientation of thestrips 16 are maintained. It can also be seen, that the strip 16 doesnot extend along the shoulders of the balloon. Thus, the strip can beelongated and can extend parallel with the axis of the balloon. FIG. 15Ashows one strip 16 for simplicity, though it will be understood that 2,3, 4, 5, or more strips could be used.

These rings 13 can be positioned over the expanded balloon 20 area andmay have different properties than the rings 12, 14 on either end of theballoon 20. As illustrated in FIG. 15A, in some embodiments, the rings13 positioned over the balloon 20 surface may be more elastic inproperty than those located on the ends of the balloon 20. This canallow the rings to accommodate the expansion and refolding of theballoon 20. In some examples, the rings used on the outer diameter ofthe balloon 20 are placed over the two ends of each separated strip. Thestrips 16 may also be glued, welded, restrained by friction fit, orotherwise attached to any of the rings described above.

In some embodiments, rows of strips and/or strip segments can be placedaround the balloon 20. Some rows may extend over the entire length ofthe balloon 20 and other rows may not. In some examples, a row mayinclude a plurality of strips in series that are separated by gaps.Placing strips in a series on the balloon can provide greaterflexibility which can improve deliverability through tortuous anatomy.

As described previously, rings 12, 14, 13 can be used to retain thestrip on the surface of the balloon 20. The rings can be connected tothe strips in any number of different ways, as described in the variousembodiments herein. In some embodiments, the ends of the strips 16 withno wedge dissectors can be used to attach to the rings. In otherembodiments, the ends with wedge dissectors can attach to the rings.

FIG. 15B illustrates another embodiment of balloon catheter. A balloon20 is shown with a cage 10 with four equally spaced rows of strips 16.Each row has two strips 16 that are laid in series. A ring 13 attachesthe adjacent strips 16 to properly secure and orient the strips 16across the surface of the balloon 20. Rings 12, 14 hold down the otherends of the strips.

The callout “A” provides an enlarged view of the distal end of theballoon 20 with cage 10. The hatching illustrated in callout “A” isprovided to help visualize and delineate the different parts of thedevice. As shown, the end of the balloon 20 includes a ring 12 thatsecures a plurality of strips 16 to the surface of the balloon 20. Theballoon 20 is disposed about a catheter 19. The ring 12 can be a heatshrink material. A wedge dissector is also shown extending through thering. The placement of the strips is further clarified in FIG. 15C whichshows how a pair of strips 16 which are laid in series such that thestrips 16 span the length of the balloon 20.

To improve flexibility, the cage 10 can have rows that are made up of agreater number of strips 16 than illustrated in FIGS. 15B and 15C. FIGS.15D-15E illustrate an example where five strips 16 are laid across thesurface of the balloon 20 in series. As noted previously, each of thesestrips 16 can be secured on the surface of the balloon 20 by a pluralityof rings 13. Callout “A” provides a cut away of the ring 13 to show thegap between the two strips 16 that are in series. As described abovewith reference to FIG. 14E, the wedge dissector can protrude through thering 13 in a variety of ways. For example, the shape of the wedgedissector can cause the wedge dissector to poke through the material ofthe ring 13. As well, the ring 13 can have a plurality of holes cut intothe rings 13 to allow the wedge dissectors to poke through.

In addition to having multiple strips in rows, the gap between thestrips in a row can also be adjusted to increase flexibility. To easemanufacturing the linear alignment in the theta direction around theradius (angle drift) and the spacing alignment between the strips 16(gap) can have a relatively broad tolerance creating greater options indeveloping the manufacturing process and choosing tools. In some cases,the gap tolerance can be ±5 mm and the angle drift ±25 degrees; ±3 mmand the angle drift ±10 degrees; and ±2 mm and the angle drift ±5degrees. Cage designs that require greater tortuosity can utilize theperiodic strip placements in a linear sequence with spaced apart strips.This can enable the balloon to manage bends and turns in anatomicalspaces with less stress on the strips and more effective pushability ofthe entire system.

As shown herein many of the strips 16 have a flat bottom. This can helpthe strips 16 sit on the surface of the balloon and to maintain theorientation of the wedge dissectors. This can prevent rotationalmovement of the strips 16 on the surface of the balloon 20.

Three unique features that all strip and ring configurations can work toachieve are 1) perpendicularity of the wedge dissectors to the balloonsurface, 2) maintaining flat and low profile of the strips on theballoon, aiding in limiting the wedge dissectors from damaging tissue onits journey, and 3) either assisting in deflation of the balloon orproducing a minimal burden on the typical balloon deflationcharacteristics. To achieve these features strips typically have a flatbottom, are bounding to the balloon with rings on either end of thestrip, are folded to limit wedge dissector interaction with tissue onits journey, and when a ring lays over the wedge dissectors the wedgedissectors poke through the rings and the majority of the wedgedissector height is still available for penetration into the vessel.Although some designs utilize rings to produce forces on the balloonenabling more effective balloon deflation by either pulling on thestrips end to end or by applying radial compression, in most designs therings can support the strips by limiting strip movement, aiding in wedgedissector orientation, and preventing the strips from separating fromthe balloon. Design features that contribute to these functionalcharacteristics include: strips that have flat bottoms enabling stableorientation of the wedge dissectors but are thin enough to be laid downtangential to the balloon or contained in a fold of the balloon duringfolding, spacing between the wedge dissectors does not have a cuttingedge enabling rings to lay in the spacing and support strip retention,and the ends of the strips can be thinnest with no wedge dissectorsenabling greater surface area for rings to bond to the strip andenabling the strip to be most flexible at the edge of the balloon whereforces are highest during catheter migration to and from site ofdeployment. It will be understood that other benefits and advantages canalso be provided.

The rings 12, 13, 14 can be attached to the strips 16 in a variety ofways. FIGS. 16A-C shows examples of the rings 12, 13, 14 secured to thestrips 16. FIG. 16A shows a material wrapped around the balloon to formrings 12, 13, 14 such that the material of the ring can be secured tomore than one strip. In some examples, as illustrated in FIG. 16B, thering 12, 13, 14 can be wrapped about a portion of each strip. This canbe accomplished in the same way as illustrated in FIG. 10, where each ofthe rings can have an upper layer and bottom layer that wraps around aportion of the strip 16. FIG. 16C illustrates a solid ring 12, 13, 14that can be attached to a portion of the balloon. A portion of the stripcan be secured to the ring.

As discussed herein, many of the embodiments can use a heat shrinkmaterial for part of, or the entire ring 12, 13, 14. Heat shrinkmaterial generally starts from an extruded tube that is cross-linkedusing a form of radiation. The tube can be stretched or otherwise formedto the desired thickness. For example, it can be stretched to a flexiblemicroscopically-thin-wall tubing, it can be made rigid from a heavy-walltubing, or it can be somewhere in-between. Cross-linking can create adiameter memory and can be designed with a shrink ratio from 2:1 up to10:1. Heat shrink typically shrinks only in the radial direction but canalso shrink in length.

Heat shrink material can be manufactured from a thermoplastic material,such as polyolefin, fluoropolymer (including fluorinatedethylene-propylene (FEP), polytetrafluoroethylene (PTFE) orpolyvinylidene fluoride (PVDF) (e.g. KYNAR)), polyvinyl chloride (PVC),neoprene, silicone, elastomer or synthetic rubber and fluoropolymerelastomer (e.g. VITON). When a flexible material is desired, such as onethat expands with a balloon, the heat shrink material can include one ormore of polyolefin, silicone, elastomer or VITON (synthetic rubber andfluoropolymer elastomer).

Heat shrink material in the form of a tube can be used to slide onto orover the strips 16. The tube can have a shrink ratio of 3:1 or higher(e.g. 3.5:1, 4:1, 4.5:1, 5:1, 6:1) and allow for gentle heat shrinkingto prevent any balloon deformation or other changing of the balloon'sproperties. The material can be flexible enough to conform to theballoon through a range of balloon diameters (such as typical withsemi-compliant balloon technology ˜0.5 mm diameter range), and may havean adhesive or other coating to support the bonding of the heat shrinkmaterial and balloon. The heat shrink material can be a thin film. Theheat shrink material may also be in the form of a sheet or multiplesheets instead of a tube.

A method of retrofitting a balloon catheter with a cage can include anyof the following steps. Positioning strips around an inflated balloon.The strips may include wedge dissectors. The strips can be positionedequally spaced around the inflated balloon. The strips can extendprimarily longitudinally. The strips may be positioned serially in rows,such as 2-6 rows, each with 2-6 strips. The strips can be attachedeither permanently or temporarily to the balloon with an adhesive. Heatshrink material can be positioned around the ends of the strips as aring. Individual rings of heat shrink material can connect to or coverends of multiple strips positioned circumferentially around the balloon.Individual rings of heat shrink material can also connect to or coverends of adjacent strips positioned serially in a row. Heat can then beapplied to shrink the heat shrink material. The balloon can be deflatedand then sterilized in preparation for use.

Turning now to FIG. 17, a schematic view is illustrated showing a detailof a cage 10. In some embodiments, the strip 16 is shown having asection 34 composed of a spring zone. The spring section of the strip 16can provide a plurality of benefits. For example, the spring section 34can increase the flexibility of the cage 10. Increasing the flexibilityof the cage 10 can allow the cage 10 to more easily pass through thetortuous geometry of a blood vessel. The spring section 34 can alsoprovide a wider base for the wedge dissectors 26, to help the wedgedissectors 26 remain in the desired orientation.

In some embodiments, the spring section 34 can interface with a surfaceof the balloon 20. The spring section can help the strip 16 to remain inthe correct position with the wedge dissectors 26 in an outwardlyprojecting orientation. In some examples, the spring section cancounteract a sideways bending moment on the spike such that the wedgedissectors 26 do not bend, flex, or change position an undesirableamount. In some embodiments, the spring section 34 can also provide thebenefit of assisting the balloon 20 in refolding post inflation. Thespring can add mechanical tension on the balloon 20 to return it to acompressed state and further aid the rings in compressing the balloon 20during deflation cycles.

The spring section 34 can have an undulating configuration and beconnected to a straight section 36. In some examples, the wedgedissectors 26 can be located on the straight section. In otherembodiments, the spring section can be sinusoidal. As illustrated inFIG. 18, the spring section is shown having a larger amplitude at theproximal end as compared to the distal end. The amplitude can decreasewhile the period increases along the spring section towards the straightsection in a distal direction. In some embodiments, one side of thespring section can have a larger amplitude than the opposite side. Insome embodiments, the spring section can be symmetrical.

FIG. 18 illustrates various embodiments of the cage 10 utilizing thespring section 34 and straight section 36. Any number of differentpatterns can be used. FIG. 19 shows a detail of wedge dissectors 26 onstraight sections 36.

Systems and methods as disclosed herein can deploy the cages and wedgedissectors in any body lumen, including vascular lumens such as arteriesand veins. The arteries could be coronary arteries, peripheral arteries,or carotid or other cerebral arteries, for example, or iliac, femoral,superficial femoral, iliac, or other peripheral vasculature, forexample. The device may also be used in any lumen or transportationvessel found in any of the respiratory, digestive, urinary,reproductive, lymphatic, auditory, optical, or endocrine systems. It isunderstood that a device for generating serrations in any one, two, ormore of these systems may take slightly different forms. Independent ofthe location the device might be used, some embodiments of devicesinclude spikes (also herein referred to as wedge dissectors, orserrating elements on a spline and an expandable mechanism to increaseand decrease the diameter of the spike features (such as a balloon) withboth attached to a base catheter-like device.

In some embodiments, as illustrated for example in FIG. 20 which is aclose-up detail view of an embodiment of a wedge dissector 200 on itsassociated strip 300, a wedge dissector 200 can include a strip-facingbase surface 202 (which may also be referred to herein as a boundedsurface). The strip-facing base surface 202 of the wedge dissector 200can be defined by the base where the wedges 200 protrude outward anddirectly continuous with a surface of the strip at the interface betweenthe wedge dissectors and the balloon. The strip could be a spline 300 orother strip-like structure. In some embodiments, this strip-facing basesurface 202 has a relatively narrow width made of a hard materialcapable of holding a sharp edge. In some embodiments, the preferredmaterial is martensitic stainless steel, with a hardness of 52 to 64 onthe Rockwell C-scale (HRC) although other materials including a polymeror co-polymer including but not limited to polyolefin, fluoropolymer(including fluorinated ethylene-propylene (FEP), polytetrafluoroethylene(PTFE) or polyvinylidene fluoride (PVDF) (e.g. KYNAR)), polyvinylchloride (PVC), neoprene, silicone, elastomer or synthetic rubber andfluoropolymer elastomer (e.g. VITON), or a combination thereof can beutilized. In some embodiments, the strip is about or no more than about0.008″, 0.010″, or 0.012″ wide (oriented circumferentially). In somecases, the width can be between about 0.006″ and about 0.020″ or betweenabout 0.004″ and about 0.030″. In some embodiments, the strip 300typically runs longitudinally the length of the working balloon edge,but can also be oriented in angles up to and including 90 degrees fromthe longitudinal axis of the balloon (or other expandable structure), orin a helical fashion at varying pitches. In some embodiments, the heightof the base strip 300 can be between about 0.004″ and about 0.010″, orbetween about 0.002″, and about 0.020″ in some embodiments.

Still referring to FIG. 20, a wedge dissector 200 can also include aradially outwardly facing surface 204 (which may be referred to hereinas an unbounded surface) that can define a top surface of the wedgedissector 200 from first (e.g., proximal) edge 206 to second (e.g.,distal) edge 208 and be configured to contact tissue, plaques, or otherstructures within the body. Also shown are anterior surface 210,posterior surface 212, and opposing lateral surfaces 214 and 216. Insome embodiments, the lateral surfaces 214, 216 extend upward generallyperpendicular to the longitudinal axes of the strips, and the radiallyoutward facing surface extends between the lateral surfaces as a linear,curved, or other geometry as described elsewhere herein at an angle tothe lateral surface/lateral surface axis. Also illustrates are strips orsplines 300 having an unbounded (e.g., superior-facing) surface 302 thatcan be coextensive with the strip-facing surface or boundary 202 of thewedge dissector 200, as well as side surfaces (e.g., 304), andinferior-facing surface 303.

FIG. 21 is a schematic illustrating several possible non-limitingembodiments of a wedge dissector. In some embodiments, the length of theradially outwardly facing surface L_(U) (e.g., radially outwardly facingsurface 204 between first edge 206 and second edge 208 of FIG. 20) isbetween about 30%, 20%, or 10% less than the total length of thestrip-facing surface L_(B) (of strip-facing surface 202 in FIG. 20). Insome embodiments, the radially outwardly facing surface length L_(U) canbe from about 50% to about 20% less than the strip-facing surface lengthL_(B), and sometimes as large as the strip-facing surface length L_(B).The radially outwardly facing surface width W_(U) is in some cases equalto or less than the strip-facing surface width W_(B), and typicallybetween or less than about 10%, 20%, 30%, 40%, or 50% of thestrip-facing surface width W_(B), or between about 20% and about to 50%less than the strip-facing surface width W_(B), and sometimes about orup to about 50%, 60%, 70%, 75%, or 80% of the strip-facing surface widthW_(B). Therefore, in some embodiments there is an angle θ that is equalto or less than about 90 degrees that defines the slope from thestrip-facing surface width W_(B) to the radially outwardly facingsurface width W_(U) on at least one of the strip-facing surface widthW_(B) edges. While in some embodiments the radially outwardly facingsurface width W_(U) is constant from edge to edge, in some embodimentsthe radially outwardly facing surface width W_(U) varies along theradially outwardly facing surface length L_(U) as described elsewhereherein, such as decreasing from a first lateral edge to a point orsegment in between the first lateral edge and the second lateral edge ofthe radially outwardly facing surface segment, and then increasing, fromthe point or segment in between the proximal edge and the distal edge,to the distal edge. In some embodiments, the relatively central segmentin between the proximal edge and the distal edge has a constant width,while the lateral segments surrounding relatively central segment havevariable, such as tapered widths.

Although the radially outward facing width W_(U) can come to a point,sloping from the strip-facing base width W_(B) of the strip-facing basesurface 202 to the radially outward facing width W_(U) of the radiallyoutward facing surface 204 in a single, constant sloped angle θ or bevelsuch as shown in FIG. 22A (end view resembling an isosceles triangle)and FIG. 22B (isometric view), it can also in some embodiments include aplurality of different angles, such as more than a single slope anglesuch as a double, triple or more bevel (e.g., a first angle for a firstsegment of the height, a second angle for a second part of the heightthat can be less than or greater than the first angle, and in some casesa third angle for a third part of the height that can be less than orgreater than the first angle, and less than or greater than the secondangle). FIG. 22C illustrates an end view and FIG. 22D illustrates anisometric view of a wedge dissector with a plurality of differing slopesand associated angles from the strip-facing base surface to the radiallyoutward facing surface, where the angle θ2 between horizontal and anupward slope after a transition point is greater than an angle θ1between the horizontal strip-facing base edge and the intersectingupward slope (in other words, the first slope S1 from the strip-facingbase edge base is less steep than a second slope S2 higher up after atransition point). FIGS. 22E and 22F illustrate an embodiment similar toFIGS. 22C and 22D except the angle θ2 is less than the angle θ1 (inother words, the first slope S1 from the strip-facing base edge base issteeper than a second slope S2 higher up after a transition point).

Alternately, some embodiments may also include a series of steps atdifferent heights where the width transitions to a narrower width andthen continues to climb in height. When a series of steps is used inplace of the bevel it can sometimes be due to fabrication limitationwhen methods other than a reel of stainless steel is honed to an edge.

The shapes of the radially outward facing edge or surface (e.g.,radially outward facing surface 204 of FIG. 20) can in some embodimentsbe the same height from one edge 206 of the radially outward facinglength or width to the other edge 208. In some embodiments, the heightalong the radially outward facing surface 204 can vary from one edge 206to the other edge 208. When the radially outward facing edge or surface204 varies, typically the radially outward facing edge has a series ofraised features herein referred to as wedge dissectors, spikes, orserrating elements 200. In some embodiments, the midpoint of theseraised features along the radially outward facing length 204 betweenedges 206, 208 is the highest point of the radially outward facingsurface. However, in some embodiments, the highest point is offset fromthe midpoint, and there may be a plurality of highest pointsinterspersed by lower point relative to the bounded/base surface 202.The maximal variation of height between edges 206, 208 of the radiallyoutward facing surface 204 of the wedge dissectors 200 and the radiallyoutward facing surface 302 of the base strip 300 between the wedgedissectors 200 can in some embodiments be less than about 80%, 70%, 60%,50%, 40%, 30%, 20%, 10%, or less than the total height of the wedgedissector 200.

In some embodiments, the base strip 300 has a roughened or otherwisetextured inferior surface to aid in adhesion to an outer surface of theunderlying balloon. The base strip can have any desired geometry such assquare, rectangular, or in some embodiments trapezoidal with the bottomsurface having a greater width, such as about or at least about 10%,20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or more of the topsurface. In some embodiments between about ⅓ and ½ of the top surface ofthe strip 300 is covered by wedge dissectors 200, while between about ½and ⅔ of the top surface are free of wedge dissectors 200.

Referring to FIG. 21, in some embodiments, the radially outward facingsurface viewed from the top can be seen as a line extending from oneedge of the radially outward facing length to the other edge of theradially outward facing length (e.g., where W_(U) is a point assuming210A is the radially outward facing surface of the device). This wouldbe analogous to a honed or “razor-sharpened” edge with no apparentwidth. In other embodiments, the top view appears as an unhoned surfacethat is slightly blunt resembling a rectangle (e.g., if 210B or 210C isthe top of the device, and assuming everything above those lines werecut off) with the width of the radially outward facing surface W_(U)being less than the strip-facing base surface W_(B) but directlycorrelated with the slope or slopes between the width edge and heightfrom the strip-facing base surface to the radially outward facingsurface. In some embodiments, the top or the radially outward facingsurface can be a line, a flat rectangle, a rounded or mounded surface(that might appear to be a rectangle or square in a 2-dimension point ofview), or take a pyramidal, wedge, trapezoidal, or other polygonalshape.

In some embodiments, an unhoned width can be a width, for example, thatis about or greater than about 1 nm, 5 nm, 10 nm, 50 nm, 100 nm, 500 nm,1 μm, 2 μm, 5 μm, or 10 μm measured at the radially outward facing edgeor surface. In some embodiments, unhoned radially outward facingsurfaces of wedge dissectors can be advantageous as being slightlyblunt/relatively less sharp than honed edges, in situations for examplewhere creating serrations, indentations, and/or microperforations in awedge dissector target, for example, is desirable rather than makingcuts through the entire luminal wall. In some embodiments, the entireradially outward facing wedge dissector surface has an unhoned width.

The shape of the wedge dissectors can take many forms, including furthernon-limiting embodiments as those shown in FIGS. 21A-G. For example,FIG. 21A illustrates wedge dissectors 200 rising from a base strip 300with a honed/sharp radially outward facing surface 204 from edge 206 toedge 208. FIG. 21B-21C illustrates wedge dissectors with chamferedsegments 780 of a radially outward facing surface on both lateral edgesthat slope or otherwise ramp upward to a honed central single point 782or edge having a length 781. The slope could be a straight line ramp, orfollow a curve as seen in FIG. 21D below. As illustrated in FIG. 21B,the wedge dissector includes lateral segments 780 of radially outwardfacing surface that increases in height, but decreases in width from afirst edge to a central mid-portion 781 having a length withminimal/negligible width, and then increases in width and decreases inwidth from the midpoint to the second edge. FIG. 21C illustrates a wedgedissector similar to FIG. 21B except that the mid-portion is a singlehoned apex point 782.

FIG. 21D illustrates a wedge dissector with a radiused radially outwardfacing surface 785 that increases in height from an edge along a firstcurved length but decreases in width from a first edge to a central zonesuch as a midpoint 786, then decreases in height and increases in widthalong a second curved length to another edge.

FIGS. 21E-21G illustrate embodiments of wedge dissectors with anunhoned, radially outward facing surface that do not include a sharphoned point or edge (e.g., having a width that is larger than that of ahoned edge). FIG. 21E illustrates an embodiment of a wedge dissectorsomewhat similar to that of FIG. 21B, except the radially outward facingsurface is completely unhoned along its length. FIG. 21F illustrates anembodiment of a wedge dissector somewhat similar to that of FIG. 21C,except the radially outward facing surface is completely unhoned alongits length. FIG. 21G illustrates an embodiment of a wedge dissectorsomewhat similar to that of FIG. 21D, except the radially outward facingsurface is completely unhoned along its length.

One commonality of the embodiments of FIGS. 21B-21G is that the widthsof the radially outward facing surfaces are greater (wider) at thelateral edges, and narrower/less wide more centrally, either at acentral point or longer central segment. The height of the radiallyoutward facing surface from one edge to the other edge can be arched orotherwise variable, e.g., with a highest point more centrally and theshortest height at one or more edges when viewed from the side. In theseembodiments, the orientation of the narrowest or thinnest (least wide)section of the radially outward facing surface can be along thelongitudinal axis of the strip, which may or may not be aligned with thelongitudinal axis of the balloon.

In other embodiments, the narrower point or segment need not besymmetric about the midpoint of the length of the radially outwardfacing surface, but can be asymmetrical/offset from the midpoint of thelength in some cases.

Independent of the geometry of the wedge dissectors, some embodimentsare characterized by having a bounded end 202 or base (e.g., the spikeshave a base the spikes are “attached” to, whether it is a spline (orstrip), a balloon, or a molded element of some sort) with a length andwidth and an radially outward facing surface 204, end or tip with alength and width. In some embodiments, the width of the radially outwardfacing end is about, or less than about 90%, 85%, 80%, 75%, 70%, 65%,60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, or less than the width ofthe strip-facing base end, or ranges incorporating any of two of theforegoing values. The width of the strip-facing base end of the wedgedissector (as well as the spline/strip) can be fixed/constant, oralternatively variable in some embodiments.

The wedge dissectors can be a number of different sizes and shapes. Insome embodiments, the wedge dissectors are about or less than about, forexample, 0.10″, 0.09″, 0.08″, 0.07″, 0.06″, 0.05″, 0.04″, 0.03″, 0.02″,or 0.01″ in length at the strip-facing base end or ranges incorporatingany of two of the foregoing values, or between about 0.01″ and about0.06″, or between about 0.01″ and about 0.04″ in length. In someembodiments, the wedge dissectors can be about or less than about 0.05″,0.04″, 0.03″, 0.025″, 0.02″, 0.015″, 0.01″, or 0.005″ in height asmeasured from the unbonded edge of the base strip, or between about0.005″ and about 0.025″ or between about 0.01″ and about 0.025″, orbetween about 0.005″ and about 0.015″ in some embodiments.

The wedge dissectors can, in some embodiments, have a wedge strip-facingbase length of about, or less than about 25 mm, 20 mm, 15 mm, 14 mm, 13mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm,or 1 mm long, or ranges incorporating any two or more of the foregoingvalues. In some embodiments the wedge dissectors have a wedgestrip-facing base length of 2 mm, 2.5 mm, or 3 mm long, or between about1 mm and about 5 mm long, or between about 1.5 mm and about 3.5 mm long.The wedge dissectors can be spaced apart in a regular or irregularfashion to increase the flexibility of the device. For example, thespace between adjacent wedge dissectors can be, for example, betweenabout 2 times to about 10 times the wedge strip-facing base length ofthe wedge dissectors, with the wedge dissectors positioned lengthwise.For example, in some embodiments, wedge dissectors with a wedgestrip-facing base length about 2.5 mm long can have about 5 mm spacesbetween them, or about 25 mm spaces between them. In some embodiments,groups of wedge dissectors can be spaced apart with a first smallerratio of, for example, about 1-4 times the strip-facing base length ofthe wedge dissectors and then a group can be spaced apart by a secondlarger ratio, for example, about 8-10 times the strip-facing base lengthof the wedge dissectors. For example, a first group of wedge dissectorswith a strip-facing base length of 2.5 mm can have 5 mm spaces betweenthem and then a second group of wedge dissectors can be spaced 20 mmfrom first group. The second group can have the same or a differentsize, shape, and or spacing as the first group.

The location of the radially outward facing surface relative to thestrip-facing base surface is not always centered or symmetric in someembodiments. In other words, the midpoint of the radially outward facingsurface can be offset from the midpoint of the strip-facing basesurface. FIGS. 23A-B and 24 illustrate an asymmetric radially outwardfacing surface as an alternate embodiment of the spikes. An asymmetricradially outward facing surface can be off center with respect to thealignment of a radially outward facing width edge directly over thestrip-facing base width edge. In this configuration only one of thestrip-facing base width edges has a tilted edge 440 climbing in heightoff of the radially outward facing surface while the other height edge442 is perpendicular, at a 90 degree (right) angle RA to thestrip-facing base surface 444, seen best in FIG. 23A. In addition, theedges of the radially outward facing surface in one or both of the widthends and/or in one or both of the length ends can be chamfered orbeveled or have a radius. In some variations, the radially outwardfacing surface location is limited to the area projected upward over thestrip-facing base surface. The radially outward facing surface can be asharp line (e.g., honed edge) or any of the described unhoned edgevariations for example. FIG. 23C-D illustrates an embodiment where thetotal volume or substantially the total volume of the wedge dissectorrises/is present over less than the entire width (or surface area) ofthe base of the strip, such as about or less than about 70%, 60%, 50%,40%, or 30% of the width or surface area of the strip, for example, andare thus the wedge dissectors are asymmetrically offset eitheranteriorly or posteriorly from the longitudinal axis of the strip.

FIG. 24 illustrates an embodiment illustrating how the radially outwardfacing surface 204 may have a varying height (increasing from firstheight 24H1 at first edge 206 to second height 24H2 at second edge 208)from the strip-facing base surface 202 and may include edge profilesthat are rounded with a radius of curvature of the radially outwardfacing length edges 206, 208. Here we see a wider radius of curvature atone edge 206 that has a shallow height 24H1 measured from thestrip-facing base surface 202 while the radius of curvature of theopposite edge 208 is narrower and has a longer height 24H2 measured fromthe strip-facing base surface 202.

In some embodiments, the various wedge dissector features describedherein can offer unique advantages to aid in delivery of the device,including but not limited to reducing vessel trauma if the radiallyoutward facing surface is positioned outside of the delivery apparatusand/or can contact the luminal wall and has the potential to scrape thevessel wall during movement through the artery. This can be the case,for example, in embodiments with wedge dissectors with unhoned, radiallyoutward facing surfaces.

In addition, not to be limited by theory, certain shapes may offer moreeffective penetration into the tissue. For instance, wedge dissectorsthat include chamfered or rounded radially outward facing edges canpotentially enter the vessel wall with less force (requires lesspressure to penetrate tissue) while still maintaining an effective microchannel to weaken the tissue and enable tissue expansion with minimalvessel trauma and cellular injury.

Furthermore, while there have been prior proposals for providing bladesor sharp edges or scoring wire on a balloon during angioplasty or otherprocedure for cutting or scoring the plaque in conjunction with balloonexpansion, these prior methods are deemed to have problems ordisadvantages which are eliminated or avoided by systems and methods asdisclosed herein. Cutting or scoring a luminal wall, such as, forexample, the plaque during angioplasty can be performed at highpressures that can result in high injury to the blood vessel. Thecutting blades, edges or scoring wire can be forced into the wall of theblood vessel at the same time that the angioplasty balloon is expandedto dilate the plaque. During this process the cutting blades, edges, orscoring wire can be forced into the vessel wall at oblique angles andcan plow up the plaque potentially increasing the tendency fordissections. In contrast, in some embodiments, wedge dissectors employcan be expanded into the plaque at low pressures so as to form precisemicroperforations, serrations, and/or indentations in a radially outwarddirection that form precise indentations, cleavage lines or planes inthe plaque or other location in the luminal wall, or other target. Theradially outward facing surface of the wedge dissector can push into theplaque or other luminal surface in small surface areas, thereby beingmuch less likely to plow up the plaque or luminal surface.

Wedge dissectors can be designed, in some embodiments, to provide aseries of oriented punctures or serrations into (but not completelythrough in some cases) a diseased vessel wall. The wedge dissectorsproduce a linear line of weakness or perforations that enable moreeffective and gentler vessel lumen expansion. The perforations can alsoserve as a pathway for pharmaceutical agents. The pharmaceutical agentscould be delivered using a drug coated balloon, either incorporated withthe device disclosed herein, or on a separate device that is usedfollowing the usage of the disclosed device. In some embodiments, thewedge dissectors can be detachable from the base strip, and/or be coatedor otherwise impregnated with one or more pharmaceutical agents for drugdelivery.

To reduce potential rigidity of the spline, or base strip, it isenvisioned that a series of reliefs on the spline can be added in someembodiments, as illustrated in FIGS. 25 and 26. The relief elements canbe produced in many different ways with the intent to have materialremoved and offer a more pliable spline for the wedges to bestrip-facing base to. Relief can be made in the base of the splineopposite the wedge dissector strip-facing base surface, at the top ofthe spline directly adjacent the wedge dissector strip-facing basesurface, or in both locations, e.g., a combination of top and bottom.The relief can also be made on the side of the spline, or aperturesstrip-facing base by other areas of the spline can be added to thespline. Any combination of top, bottom, side or through apertures can beadded to the spline to offer relief.

In some embodiments, as illustrated in FIGS. 25 and 26, the strip 300can have relief holes or slits located at the top, bottom, centered oroff center that are either circular, rectangular, linear, triangular, orelliptical or combinations thereof (See FIGS. 25 and 26). The stripsoffer a supporting base infrastructure, intended to be flexible andfollow the movement of the balloon, for the wedges to be orientedcorrectly.

The relief holes illustrations as shown in FIGS. 25 and 26 can bespecifically designed to offer a pathway for balloon-basedpharmacological agents to migrate through; in addition, they offerstrain relief in the surface to enhance the deliverability of the devicein tortuous anatomy. FIGS. 25A-C illustrate embodiments of wedgedissectors with reliefs 502 on the inferior surface 500 of the strips300 opposite the bounded surface of the wedge dissectors 200. FIG. 25Aillustrates an embodiment where the reliefs 502 are regularly spacedapart approximately a length of the bounded surface of each wedgedissector 200. FIG. 25B illustrates an embodiment where the reliefs 502are regularly spaced apart 50% or less of the length of the boundedsurface of each wedge dissector 200. FIG. 25C illustrates an embodimentwhere each relief 502 is spaced apart 50% or less of the length of thebounded surface of each wedge dissector 200, but the reliefs 502 aregrouped only under the wedge dissectors and are not present under thestrip sections in between the wedge dissectors. In other embodiments,the reliefs 502 are grouped only under the strip sections in between thewedge dissectors, but not under the strip sections directly below thewedge dissectors.

FIGS. 25D-25E illustrates an embodiment where the reliefs 502′ arepresent on the top (bounded or superior-facing surface 302) of the stripin between the wedge dissectors. In FIGS. 25D and 25E, the reliefs formdepressions in the superior-facing surface 302 of the strips in betweenwedge dissectors with a generally curved based as illustrated in FIG.25D, and a relatively more square or rectangular base as illustrated inFIG. 25E, with or without rounded edges. FIG. 25F is an embodimentcombining two different kinds of reliefs 502 found in the embodiments ofFIGS. 25C and 25D. Other permutations of combinations are also possible,depending on the desired clinical result. FIGS. 25G and 25H illustrateother embodiments where the reliefs 502 are on an anterior 304 and/orposterior side surface of the strip 300. FIG. 25G illustrates generallypyramidal-shaped reliefs 502, while FIG. 25H illustrates generallyarcuate reliefs 502. The reliefs can be spaced axially apart from thewedge dissectors as shown, and/or spaced axially aligned with wedgedissectors in other embodiments. FIGS. 25I and 25J illustrateembodiments where the reliefs 502 take the form of vertically (FIG. 25I)or horizontally (FIG. 25J) oriented through-channels, which can bespaced axially apart from the wedge dissectors as shown, or in anotherconfiguration. In some embodiments, the reliefs can be oriented at anoblique angle to the longitudinal axis of the strip. FIG. 25Killustrates an embodiment where the reliefs 502 take the form of slotson the anterior and/or posterior side surfaces, bounded base surface,and/or other locations.

To aid in removal of material fabrication from the initial blade, thestrips can include tabs along the base or bonded surface in someembodiments. The tabs can aid in controlling long strips from vibrationor movement during the material removal. Once fabrication is completed,the tabs are then removed. In some embodiments, the tabs have an insetthat they sit at the base of the strip. In some embodiments, insetreliefs can serve as the tabs, and be advantageous during themanufacturing process, when several strips are, for example, laser cutfrom the same sheet of source material. In some embodiments, acomplementary protrusion (e.g., a tab or related structure) on orconnected to an adjacent area of the source material to be laser cut canfit into an inset relief of a strip adjacent to the source material tomaintain proper alignment of the strips during lasercutting/manufacturing. This can keep the strips in place during lasercutting, and prevent undesired migration and misalignment of a striprelative to an adjacent material area due to, for example, laservibrations, which can decrease product yields. In some embodiments,reliefs for manufacturing stability purposes need not be inset and cantake the form of tabs that protrude outwardly from the base of the tab.In some embodiments, these tabs are later removed by laser cutting orother methods prior to bonding or other attachment to the outer surfaceof the balloon, to prevent inadvertent puncture of the balloon. Someembodiments are illustrated in FIGS. 25L and 25M, which schematicallyillustrate strips 300 with wedge dissectors 200 during the strip andmanufacturing process. Also shown is tab 580, which can be laser cut outof the source material, and be connected with one end at an adjacentarea of the source material 581 and the other end inset in an insetrelief 502 in, for example, an inferior surface of the strip 300. Theinset relief 502 can be any pattern as previously described, forexample, in FIGS. 25A-25K or others, and in some embodiments are shownunderneath the wedge dissector 200. FIG. 25M illustrates the tab 580which can be cut into segments 588, 589 following the manufacturingprocess when it is no longer required to hold the strip 300 in placewith respect to adjacent source material 581, and the strip 300 can thenbe separated for attachment to a balloon or other device. The inset canallow for the tab to be removed while minimizing that amount of materialthat could potentially hang below the base of the strip which mightinterfere with the bonding of the strip to the balloon or otherexpansion device.

In some embodiments, balloons can be pleated and crimped down to thevery narrow profile allowing the device to be delivered through andintroducer sheath with a narrow diameter. Once the balloon has beendeployed and deflated, the post-inflated balloon profile can be largerthan its original pleated and crimped down diameter. This new profilemay have strips that sit proud of the balloon profile potentiallyscraping the arterial wall or snagging on the opening of an accessorydevice such as an introducer sheath. The following elements, which arein general described as ramps, can address this potential issue,according to some embodiments.

FIG. 25N illustrates schematically an embodiment of a ramp 680 ofadhesive or other material is placed at (e.g., over) one, as shown, orboth lateral ends 333 of some or all of the strips 300. This can be, insome cases, in addition to adhesive placed at other locations such asunder the strips (e.g., on the inferior surface of the strips 300) toattach the strips 300 to the balloon. The ramp 680 can offer aneffective flexible interface between the edge of the flexible balloon(not shown) and the semi-rigid strip 300, as the ramp 680 can be made ofa material (e.g., an adhesive) that is relatively more flexible thanthat of the strip 300. The ramp 680 can be designed in some embodimentsto gently slope from the balloon surface (not shown) to the edge ofstrip. In some embodiments, the adhesive ramps 680 can advantageouslyboth retain strips and offer protection from undesired strip interaction300 with ancillary devices during a procedure.

In some embodiments, a feature that can be incorporated into the balloonelement is a cone ramp. The cone ramp feature can be implemented inseveral ways. In one embodiment, the cone ramp is fabricated by taking acone configuration for a larger balloon, for example taking a cone for a6 mm balloon, or 5.5 mm balloon and incorporating it using known methodsto be attached to a 5 mm balloon. One such embodiment is shownschematically in FIG. 25O. The cone 970 can have in some cases an outerdiameter that is larger than that of the outer diameter of the balloon960, such as about or at least about 5%, 10%, 15%, 20%, or more thanthat of the outer diameter of the balloon 960, or between about 5% andabout 20% larger than that of the outer diameter of the balloon 960 insome embodiments. The relatively larger cone 970 will sit proud of theballoon 960 generating a lip 972 at the intersection of the balloonbody. The lip 972 can be beneficial in reducing the potential of themetal strip edges to be snagged or lifted off when the balloon isdeflated and retracted through the introducer catheter.

In some embodiments, illustrated in FIG. 25P, included are a series ofrails 980 along the cone 970 to serve as support or stiffeningstructures, and assist in collapsing the balloon 960 as it enters anintroducer catheter (not shown). In some embodiments, the rails 980 areoriented/align with the longitudinal axes of the strips, furtheringenhancing the function of pushing the strips toward the middle of theballoon as the cone is pulled through the introducer.

In some embodiments, also disclosed herein are balloons that can havedepressions in the outer surface of the balloon for strip attachment. Aseries of depressions can be produced on the surface of the balloon. Thedepressions can, in some embodiments, configured to be wide enough andlong enough to allow the strips to be placed within, such as entirelywithin the depression. The depths of the depressions can be sized tolimit the likelihood that the strips could get caught on the distalopening of the introducer during balloon retraction.

The use of the through-holes or microchannels either in the spline or onthe spline sides can offer a mechanism for a therapeutic agent such as,for example, one or more drugs, nanoparticles, and/or stem celltransport from the balloon surface into the diseased luminal surfacethrough capillary or diffusion action and/or utilization of the balloonpressure forcing the drug, nanoparticles, and/or stem cells through themicro channels on to the surface or into the diseased site.Alternatively, the microchannels or modified surfaces can provide areservoir for drug, nanoparticles, or stem cells or other therapeuticsto be placed and protected during transport to the diseased site. Insome embodiments, the drug may be any drug known in the art. In someembodiments, examples of drugs that may be suitable for use in themethods and devices of this invention depending, on the specific diseasebeing treated, and with consideration of the physical properties of thedrug, include, without limitation, anti-restenosis, pro- oranti-proliferative, anti-inflammatory, anti-neoplastic, antimitotic,anti-platelet, anticoagulant, antifibrin, antithrombin, cytostatic,antibiotic, anti-enzymatic, anti-metabolic, angiogenic, cytoprotective,angiotensin converting enzyme (ACE) inhibiting, angiotensin II receptorantagonizing and/or cardioprotective drugs.

Examples of antiproliferative drugs include, without limitation,actinomycins, taxol, docetaxel, paclitaxel, sirolimus (rapamycin),biolimus A9 (Biosensors International, Singapore), deforolimus, AP23572(Ariad Pharmaceuticals), tacrolimus, temsirolimus, pimecrolimus,zotarolimus (ABT-578), 40-O-(2-hydroxy)ethyl-rapamycin (everolimus),40-O-(3-hydroxypropyl)rapamycin (a structural derivative of rapamycin),40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin (a structural derivative ofrapamycin), 40-O-tetrazole-rapamycin (a structural derivative ofrapamycin), 40-O-tetrazolylrapamycin, 40-epi-(N-1-tetrazole)-rapamycin,and pirfenidone.

Examples of anti-inflammatory drugs include both steroidal andnon-steroidal (NSAID) anti-inflammatories such as, without limitation,clobetasol, alclofenac, alclometasone dipropionate, algestone acetonide,alpha amylase, amcinafal, amcinafide, amfenac sodium, amiprilosehydrochloride, anakinra, anirolac, anitrazafen, apazone, balsalazidedisodium, bendazac, benoxaprofen, benzydamine hydrochloride, bromelains,broperamole, budesonide, carprofen, cicloprofen, cintazone, cliprofen,clobetasol propionate, clobetasone butyrate, clopirac, cloticasonepropionate, cormethasone acetate, cortodoxone, deflazacort, desonide,desoximetasone, dexamethasone, dexamethasone dipropionate, dexamethasoneacetate, dexmethasone phosphate, momentasone, cortisone, cortisoneacetate, hydrocortisone, prednisone, prednisone acetate, betamethasone,betamethasone acetate, diclofenac potassium, diclofenac sodium,diflorasone diacetate, diflumidone sodium, diflunisal, difluprednate,diftalone, dimethyl sulfoxide, drocinonide, endrysone, enlimomab,enolicam sodium, epirizole, etodolac, etofenamate, felbinac, fenamole,fenbufen, fenclofenac, fenclorac, fendosal, fenpipalone, fentiazac,flazalone, fluazacort, flufenamic acid, flumizole, flunisolide acetate,flunixin, flunixin meglumine, fluocortin butyl, fluorometholone acetate,fluquazone, flurbiprofen, fluretofen, fluticasone propionate,furaprofen, furobufen, halcinonide, halobetasol propionate, halopredoneacetate, ibufenac, ibuprofen, ibuprofen aluminum, ibuprofen piconol,ilonidap, indomethacin, indomethacin sodium, indoprofen, indoxole,intrazole, isoflupredone acetate, isoxepac, isoxicam, ketoprofen,lofemizole hydrochloride, lomoxicam, loteprednol etabonate,meclofenamate sodium, meclofenamic acid, meclorisone dibutyrate,mefenamic acid, mesalamine, meseclazone, methylprednisolone suleptanate,momiflumate, nabumetone, naproxen, naproxen sodium, naproxol, nimazone,olsalazine sodium, orgotein, orpanoxin, oxaprozin, oxyphenbutazone,paranyline hydrochloride, pentosan polysulfate sodium, phenbutazonesodium glycerate, pirfenidone, piroxicam, piroxicam cinnamate, piroxicamolamine, pirprofen, prednazate, prifelone, prodolic acid, proquazone,proxazole, proxazole citrate, rimexolone, romazarit, salcolex,salnacedin, salsalate, sanguinarium chloride, seclazone, sermetacin,sudoxicam, sulindac, suprofen, talmetacin, talniflumate, talosalate,tebufelone, tenidap, tenidap sodium, tenoxicam, tesicam, tesimide,tetrydamine, tiopinac, tixocortol pivalate, tolmetin, tolmetin sodium,triclonide, triflumidate, zidometacin, zomepirac sodium, aspirin(acetylsalicylic acid), salicylic acid, corticosteroids,glucocorticoids, tacrolimus and pimecrolimus.

Examples of antineoplastics and antimitotics include, withoutlimitation, paclitaxel, docetaxel, methotrexate, azathioprine,vincristine, vinblastine, fluorouracil, doxorubicin hydrochloride andmitomycin.

Examples of anti-platelet, anticoagulant, antifibrin, and antithrombindrugs include, without limitation, heparin, sodium heparin, lowmolecular weight heparins, heparinoids, hirudin, argatroban, forskolin,vapiprost, prostacyclin, prostacyclin dextran,D-phe-pro-arg-chloromethylketone, dipyridamole, glycoprotein IIb/IIIaplatelet membrane receptor antagonist antibody, recombinant hirudin andthrombin, thrombin inhibitors such as ANGIOMAX® (bivalirudin, fromBiogen), calcium channel blockers such as nifedipine, colchicine, fishoil (omega 3-fatty acid), histamine antagonists, lovastatin, monoclonalantibodies such as those specific for Platelet-Derived Growth Factor(PDGF) receptors, nitroprusside, phosphodiesterase inhibitors,prostaglandin inhibitors, suramin, serotonin blockers, steroids,thioprotease inhibitors, triazolopyrimidine, nitric oxide or nitricoxide donors, super oxide dismutases, super oxide dismutase mimetic and4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO).

Examples of cytostatic or antiproliferative drugs include, withoutlimitation, angiopeptin, angiotensin converting enzyme inhibitors suchas captopril, cilazapril or lisinopril, calcium channel blockers such asnifedipine; colchicine, fibroblast growth factor (FGF) antagonists; fishoil (ω-3-fatty acid); histamine antagonists; lovastatin, monoclonalantibodies such as, without limitation, those specific forPlatelet-Derived Growth Factor (PDGF) receptors; nitroprusside,phosphodiesterase inhibitors, prostaglandin inhibitors, suramin,serotonin blockers, steroids, thioprotease inhibitors,triazolopyrimidine (a PDGF antagonist) and nitric oxide.

Examples of ACE inhibitors include, without limitation, quinapril,perindopril, ramipril, captopril, benazepril, trandolapril, fosinopril,lisinopril, moexipril and enalapril.

Examples of angiotensin II receptor antagonists include, withoutlimitation, irbesartan and losartan.

Other therapeutic drugs that may find beneficial use herein include,again without limitation, alpha-interferon, genetically engineeredendothelial cells, dexamethasone, antisense molecules which bind tocomplementary DNA to inhibit transcription, and ribozymes, antibodies,receptor ligands such as the nuclear receptor ligands estradiol and theretinoids, thiazolidinediones (glitazones), enzymes, adhesion peptides,blood clotting factors, inhibitors or clot dissolving drugs such asstreptokinase and tissue plasminogen activator, antigens forimmunization, hormones and growth factors, oligonucleotides such asantisense oligonucleotides and ribozymes and retroviral vectors for usein gene therapy, antiviral drugs and diuretics.

In other embodiments, a combination of any two, three, or other numberof the foregoing drugs or other therapeutic agents can be utilizeddepending on the desired clinical result.

One method for laying down drugs, nanoparticles, stem cells or othertherapeutics in specific regions such as the relief holes is the use ofa direct write process, e.g., MICRO-PENNING (MICROPEN Technologies,Honeoye Falls, N.Y.), to deposit material onto a surface. In general,the term “direct write” describes a printing or patterning method thatemploys a computerized, motion-controlled stage with a motionlesspattern generating device to dispense flowable materials in a designedpattern onto a surface. MICRO-PENNING is a flow-based micro-dispensingtechnique in which printed materials are extruded with a high degree ofcontrol through a syringe and a precision pen tip. The pen tip “rides”on the surface of the material, not touching the substrate surface andis capable of place precise amount of materials in precise locations.

FIG. 26 illustrates an embodiment of a strip 500 with reliefs 502 on theinferior surface of the strips 300 opposite the bounded surface of thewedge dissectors 200, with additional relatively larger apertures 503 inbetween wedge dissectors 200 which can be configured to facilitatebonding of the strip 300 to the underlying balloon, which can be asdisclosed, for example in PCT Pub. No. WO 2016/073490 published on May12, 2016 and hereby incorporated by reference in its entirety. Theapertures 503 can be relatively oval shaped, circular, or any othershape depending on the desired clinical result.

In some embodiments, the longitudinal axis of the strips arelongitudinally oriented along the balloon and spaced apart from eachother. In some embodiments, the strips do not completely cover thelength of the balloon. For example, in one embodiment an 80 mm longballoon can have strips that measure 76.6 mm. While the length of thestrip can be the same as the defined working balloon length, in someembodiments the length of the strip is shorter than the defined workingballoon length to allow for balloon contraction that is typicallyobserved when a balloon goes to rated burst pressure. The length of eachstrip can in some cases be no more than about 15%, 10%, 9%, 8%, 7%, 6%,5%, 4%, 3%, 2%, or 1%, or between about 2% and about 8%, between about3% and about 6%, or between about 4% and about 5% shorter than theoverall working balloon length. In some embodiments, the working balloonlength does not include the lengths of the cones.

In some embodiments, part of the strip, e.g., the base of the strip(e.g., the inferiormost surface configured to be attached to the outersurface of the balloon) can be roughened to aid in adhesion.

Spikes (e.g., serrating elements or wedge dissectors) can be fabricatedin many different manufacturing methods and in a large range of shapes.Regarding the manufacturing processes, the devices may be fabricatedusing one or more additive or subtractive processes. Additive processessuch as high energy vapor deposition, for instance laser chemical vapordeposition, self-assembly techniques, polymer/metal 3D printing,selective laser sintering, powder printers, or other stereo lithographicare a few such options but other additive processes may be used.Alternatively, subtractive processes such as etching, CNC milling, lasercutting, water jet, or electrical discharge machining are just a fewexamples but other subtractive processes may be used.

In some embodiments, a method of fabrication includes the use of a reelof martensitic stainless steel, such as for example a 300 or 400 seriesstainless steel with a hardness of about 52 to about 64 on the RockwellC-scale (HRC) although other materials can be used. The reel is thenhoned on one or both edges of the steel. In some embodiments, the steelis in the form of a thin reel strip about 0.007″ to about 0.015″ thickand between about 0.25″ to about 0.75″ wide, but can range between0.005″ and about 0.005″, and 0.020″ and between 0.15″ and 1″ wide. Insome embodiments, the tolerance of the thickness and width of the reelis greater on the higher end and can have a thickness greater than about0.020″ and a width greater than about 1″. The honed edge can be a singlehone or two or more honed angles (as illustrated, for example in FIGS.21 and 22). In some embodiments, when the angle of the honed edges aremeasured as the slope from the bounded end to the height of theunbounded end shown in FIG. 21, the angle of the honed edge can be, forexample, greater than about 75 degrees. But when more than one honedangle is used, then the tip angle is can be less than, for example,about 75 degrees. In some embodiments, the honed edge has an angle ofabout or at least about 70, 75, 80, 85, 90 degrees or greater as itmoves toward the honed edge in a series of bevels. In addition to thehoned edge, independent of the number of honed angles, in someembodiments a separate and additional edge is generated at the very tipof the unbound edge of the strips. When added, the additional tip edgeheight from the honed edge to the unbounded edge is often very short andtypically has a much larger angle than the overall honed edge.Independent of the number of honed angles used, the unbounded tip width,W_(u), can be described as the radius of the tip. The unbounded tipwidth, Wu is the penetrating edge into the lesion, when the width is, insome cases, less than about 0.01″ or 0.005″, the surface area isminimized to have a less pronounced contact surface with the vesselenabling a reduced amount of energy requirement for penetration. Whenthe tip is configured for penetration into harder surfaces such ascalcium beds, in some cases either a more obtuse angle or the removal ofthe unbound tip at a greater distance from the unbounded surface canproduce a wider tip edge (see FIG. 21, Wu). Not to be limited by theory,this wider edge distributes the load across the larger surface areagenerating a more effective resistance to tip deformation when the tipis pressured into rigid tissue surfaces. Once the reel is sharpened itis stamped to a desired length of blades. In some embodiments, the reelis hardened and then stamped to the desired length. Independent of whenthe stamping occurs, the blades can in some cases be passivated andhardened above, e.g., about HRC 45. but more typically in a range offrom about HRC 58 to about HRC 62. The hardened blade can then be lasercut, stamped, EDM'ed or another precise metal shaping technology withspikes, serrating elements or wedge dissectors utilized. In some cases,the serrated elements are processed on the reel and then hardened andpassivated. In some embodiments of strips where the tip is not asharpened honed edge, the tip of the blade, that was produced during thereel sharpening step, is removed during the wedge dissector and stripmanufacturing step. In some cases, the material removal is design tostart a distance, such as from about 0.0001″ to about 0.003″ below thehoned edge, or from about 0.0001″ to about 0.0005″ is removed from thehoned edge, producing a flat top as illustrated in FIG. 21. The thinnestedge remaining (now a flat top in some cases) on the previously honededge side is what will become the unbounded surface of the strip.

In some embodiments, disclosed are methods for attaching the strips. Themethods can include any number of processing steps that provideseffective strip retention, perpendicular orientation, and structuralstability during the fabrication and use. In one embodiment the boundedsurface is typically coated with a base coat of an appropriate material,such as a polymer, e.g., polyurethane through a controlled dippingprocess producing a uniform layer of polyurethane. The coating is driedand typically 3 or 4 strips are aligned with a strip alignment mechanismor jig and glued with a medical grade cyanoacrylate into place atpredetermined orientations. The number of strips and the periodicity canvary from, for example, 1 to 8 and is typically associated with the samenumber of balloon folds but can be less than the number of folds and theperiodicity can be non-sequential. Once the strips are bonded to theballoon surface, a single or series of multiple top coats or retentionlayers, are placed over the metal interrupted scoring elements or wedgedissectors to retain the strips and protect the balloon from the thintips of the scoring elements. In some embodiments, these layers follow asimilar process as the base or pre coat using a controlled dippingprocess producing one or more uniform layers of urethane orpolyurethane. Once the retention layer or layers are cured a layer ofhydrophilic or other coating may be apply to decrease balloon frictionand increase the balloons deliverability and retrievability. Whenincorporated, the outer slip coating as can increase the functionalityof the balloon by reducing the force to insert and retract the device.

FIG. 27 illustrates a schematic cross-sectional view of a strip andwedge dissector operably attached to the outer surface of a balloon,according to some embodiments of the invention. A polymer layer,typically thin (e.g., from 0.0001″ to 0.0009″), or about or less thanabout 0.001″ in some embodiments, such as to limit increasing theballoon diameter profile, can be used as a base coat (layer 270A)covering the outer balloon surface. This base coat 270A offers aninterface bonding layer for the interrupted scoring element to theballoon surface. This layer 270A can be made of the same or similarpolymer chemistry as other layers while offering a chemical, mechanical,or electromagnetic bond to the balloon surface. This base coat layer270A can be configured to and potentially capable of reducing theinterface strain between the balloon outer surface and the bondingsurface of the metal scoring element. Strain between the two surfaces isreduced by allowing an adhesive layer 270E and the scoring element 200to be sandwiched within a polymer matrix independent and somewhatisolated from the balloon strain during balloon expansion and pressure.Although typical base coats 270A are polymers, e.g., urethane orpolyurethane this layer can be a variety of other materials. In someembodiments, the coating could include silicone and hydrophilic coatingsinvolving hydrogel polymers or the like, such as polymer networks of avinyl polymer and an uncrosslinked hydrogel, for example. Polyethyleneoxide (PEO) is an example of a hydrogel. An example of a vinyl polymeris neopentyl glycol diacrylate (NPG). The deposition of the layer can bedone by single or a series of dips of a balloon or matrix of balloonsinto a polymer bath under controlled insertion and extraction conditionsat controlled rates in both or in one direction. Alternately, layers canbe deposited at Angstrom layers through self-assembly of monolayersusing known and practiced self-assembly techniques, typically employingsurface ionic charging.

Still referring to FIG. 27, a bonding layer 270E between the metalscoring element and the basecoat can typically be thin (0.0001″ to0.0005″) but can be as thick as 0.001″ in some embodiments and thinenough such as to limit increasing the balloon diameter profile. Theadhesive layer 270E can be a cyanoacrylate but can be made from otherbonding materials that offer a chemical, mechanical, or electromagneticbond between the basecoat 270A and the bonding surface of the metalscoring element. This layer 270E can be seen as the functional layer atjoining the bonding surface of the metal scoring element to the balloonand sometimes is the only layer between the bonding surface of the metalscoring element and the outer balloon surface. This layer 270E can beone or more adhesive products. In one preferred embodiment the adhesivelayer 270E is a single adhesive with the low viscosity allowing awicking of the adhesive along the interface of the bonded surface of themetal scoring element and the base coat. In some embodiments, anadhesive dries quickly, allowing successive layers to be applied on thetop of the adhesive layer with minimal curing delay. In other methods offabrication, a more viscous adhesive layer can be placed at both ends ofthe bottom of the strips or periodically between the bonding surface ofthe metal scoring element and the base layer allowing non-glued sectionsto be free or unbonded. In still another method more than one adhesivecan be used. For instance, a more viscous adhesive can be used on eitherend of the bonding surface of the metal interrupted scoring elements andthen followed by wicking adhesive on some or all of the unbondedsections. In some embodiments, one (e.g., a single layer) two, or moreretention layers (two layers shown in FIG. 27) 270B, 270C can be presentover the base layer 270A as well as the scoring element. A polymerretention layer can in some embodiments be similar to, and havedimensions as described above for the base layer with enough propertiessuch that the base 270A and retention 270B, 270C layers produce aneffective bond between the layers. In some cases, the retention layer(s)can be designed to offer a similar thickness as the base layer whileother times it may be useful to have the retention layers slightlythicker than the base layer. Thicker base and/or retention layers can insome circumstances offer greater puncture resistance and increaseddurability of the balloon against potential puncturing from the metalinterrupted scoring elements, any sharp edges from implants left in thebody, or from sharp edges found in severely calcified disease vesselsfor example. In some embodiments, an outer slip layer 270D can also bepresent, above the retention layer(s) over the balloon and/or scoringelements. A variety of hydrophilic coatings are commercially availableto reduce friction and offer increased navigation of balloons throughtortuous and narrow anatomical features. In some embodiments, theballoon surface can be fully encased in a hydrophilic coating while inother embodiments the balloon can be coated after pleating or afterpleating and crimping and therefore only surfaces that will typically beexposed during delivery are coated with the hydrophilic coat. Typicalhydrophilic coats are a few microns thick and can be as thin as about 10Angstroms in some embodiments.

In some embodiments, the adhesive can be applied separately to theballoon and to the strips and then both components are then bondedtogether. A template can be used to ensure proper positioning of thescoring elements along the surface of the balloon.

A retention polymer layer 270B, 270C can be typically similar to thebase layer with enough properties such that the base and retentionlayers produce an effective bond between the layers. Sometimes theretention layer(s) can be designed to offer a similar thickness as thebase layer while other times it may be useful to have the retentionlayers slightly thicker than the base layer, such as about or no morethan about 20%, 15%, 10%, or 5% thicker in some cases. Thicker baseand/or retention layers offer greater puncture resistance and increaseddurability of the balloon against potential puncturing from the metalinterrupted scoring elements, any sharp edges from implants left in thebody, or from sharp edges found in severely calcified disease vessels.In some embodiments with a plurality of retention layers 270B, 270C, thelayers can be made of the same or differing materials.

A variety of hydrophilic coatings are commercially available to reducefriction and offer increased navigation of balloons through tortuous andnarrow anatomical features. In some embodiments, layer 270D of FIG. 27can be a hydrophilic slip layer. In one preferred embodiment the balloonsurface can be fully incased in a hydrophilic coating while in otherembodiments the balloon can be coated after pleating or after pleatingand crimping and therefore only surfaces that will typically be exposedduring delivery are coated with the hydrophilic coat. Typicalhydrophilic coats are a few microns thick and can be as thin as, forexample 10 Angstroms.

The height of the wedge dissectors, strips, and layers of the outerballoon encapsulation process can be viewed as a cage for use with anexpandable member such as a medical balloon, such as an angioplastyballoon or as part of a medical procedure involving a medical balloon orother expandable member. In order to effectively perform key hole orcatheter based surgery, the ability to fold the balloon to a fraction ofthe diameter of the intended inflation diameter can be of value.Therefore the balloon and in some cases the cage are typically foldedwhere the profile of the folded balloon can be effectively used. In onesuch embodiment the cage is folded in a manner that offers orientationof the spikes such as to avoid puncturing the balloon or scraping theintima of the lumen during delivery and removal, as illustrated in FIG.28. FIG. 28 illustrates the balloon 1000 with a plurality of pleats1002, and strips 300 and associated wedge dissectors 200 in between thepleats, thus allowing a single strip 300 with its plurality of wedgedissectors 200 to lie between two pleats 1002. A pleating tool wasdesigned that offers effective orientation of the spikes and splines.The pleating tool can have a series of pleating wedges where each wedgeoffers the ability of the crimp the balloon between the wedges as thewedge elements are closed down onto the balloon. Due to the bulk of thespline elements and desire to minimize contact, and potential damage tothe wedge heads, the wedges are designed with a series of pockets thatrun the length of the wedge heads. The pockets in the wedge heads offerthe ability of the spline features to rest within said pockets andlimits the spline to wedge contact. The pockets can also offer theability to aid in orientation of the spline and spike features such thatthe orientation of the features limits contact with the balloon, such asover folding, and limits orientation, such as perpendicular orientationto the balloon, that might produce scraping of the intima of the vesselduring transport of the device on said balloon. One such orientation ofthe spikes might be at a tangential orientation, an apparent lying down,to the balloon surface as illustrated in FIG. 28.

Various other modifications, adaptations, and alternative designs are ofcourse possible in light of the above teachings. Therefore, it should beunderstood at this time that within the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein. It is contemplated that various combinations or subcombinationsof the specific features and aspects of the embodiments disclosed abovemay be made and still fall within one or more of the inventions.Further, the disclosure herein of any particular feature, aspect,method, property, characteristic, quality, attribute, element, or thelike in connection with an embodiment can be used in all otherembodiments set forth herein. Accordingly, it should be understood thatvarious features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the disclosed inventions. Thus, it is intended that the scopeof the present inventions herein disclosed should not be limited by theparticular disclosed embodiments described above. Moreover, while theinvention is susceptible to various modifications, and alternativeforms, specific examples thereof have been shown in the drawings and areherein described in detail. It should be understood, however, that theinvention is not to be limited to the particular forms or methodsdisclosed, but to the contrary, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the various embodiments described and the appended claims.Any methods disclosed herein need not be performed in the order recited.The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication. For example,actions such as “creating microperforations in an arterial plaque”includes “instructing the creating of microperforations in an arterialplaque.” The ranges disclosed herein also encompass any and all overlap,sub-ranges, and combinations thereof. Language such as “up to,” “atleast,” “greater than,” “less than,” “between,” and the like includesthe number recited. Numbers preceded by a term such as “approximately”,“about”, and “substantially” as used herein include the recited numbers(e.g., about 10%=10%), and also represent an amount close to the statedamount that still performs a desired function or achieves a desiredresult. For example, the terms “approximately”, “about”, and“substantially” may refer to an amount that is within less than 10% of,within less than 5% of, within less than 1% of, within less than 0.1%of, and within less than 0.01% of the stated amount.

1-20. (canceled)
 21. A medical balloon catheter, comprising: an elongatemember comprising a lumen, the elongate member defining a longitudinalaxis; an expandable balloon connected to the elongate member proximate adistal end of the elongate member; a plurality of strips, each strip ofthe plurality of strips including a plurality of wedge dissectors spacedapart along a surface of each strip, each strip extending longitudinallyalong an outer surface of the expandable balloon, a ramp of materialcovering lateral ends of each of the strips, the material beingrelatively more flexible than that of each of the strips; a base layeron the outer surface of the expandable balloon; and a bonding layer ontop of the base layer and on an underside of each of the plurality ofstrips; wherein the wedge dissectors comprise a strip-facing basesurface directly adjacent the surface of each of the strips, an unhonedradially outward facing surface having a length between a proximal edgeof the unhoned radially outward facing surface and a distal edge of theunhoned radially outward facing surface and defining a height of eachwedge dissector, and lateral surfaces between the strip-facing basesurface and the unhoned radially outward facing surface, wherein theunhoned radially outward facing surface has a first width at theproximal edge, a second width smaller than the first width between theproximal edge and the distal edge, and a third width at the distal edgelarger than the second width, wherein the expandable balloon comprises aplurality of pleats extending from the outer surface and spaced apartfrom the plurality of strips, wherein the expandable balloon comprises afirst reduced configuration in which the wedge dissectors of each striplie between two adjacent pleats such that a longitudinal axis of eachwedge dissector of each strip is in a tangential non-perpendicularorientation with respect to the outer surface of the expandable balloondirectly below each wedge dissector of each strip, and wherein theexpandable balloon comprises a second expanded configuration wherein thelongitudinal axis of each wedge dissector of each strip is in aperpendicular orientation with respect to the outer surface of theexpandable balloon directly below each wedge dissector of each strip,wherein the ramp of material slopes from the outer surface of theballoon to the lateral ends of each of the strips.
 22. (canceled) 23.The medical balloon catheter of claim 21, wherein the ramp of materialcomprises an adhesive.
 24. The medical balloon catheter of claim 21,wherein each strip of the plurality of strips comprises a texturedsurface.
 25. The medical balloon catheter of claim 21, furthercomprising a plurality of tabs on an inferior-facing surface of each ofthe plurality of strips opposite the wedge dissectors.
 26. The medicalballoon catheter of claim 21, further comprising a plurality of reliefson each of the plurality of strips.
 27. The medical balloon catheter ofclaim 21, wherein the base layer comprises a polymer.
 28. The medicalballoon catheter of claim 21, wherein the bonding layer comprises acyanoacrylate.
 29. The medical balloon catheter of claim 21, furthercomprising a first retention bonding layer and a second retentionbonding layer on top of the bonding layer, wherein the first retentionbonding layer and a second retention bonding layer comprise the samematerial. 30-40. (canceled)
 41. A medical balloon catheter, comprising:an elongate member comprising a lumen, the elongate member defining alongitudinal axis; an expandable balloon connected to the elongatemember proximate a distal end of the elongate member; a plurality ofstrips, each strip of the plurality of strips including a plurality ofwedge dissectors spaced apart along a surface of each strip, each stripextending longitudinally along an outer surface of the expandableballoon, a ramp of material covering lateral ends of each of the strips,the material being relatively more flexible than that of each of thestrips; a base layer on the outer surface of the expandable balloon; anda bonding layer on top of the base layer and on an underside of each ofthe plurality of strips; and a first retention bonding layer and asecond retention bonding layer on top of the bonding layer, wherein thefirst retention bonding layer and a second retention bonding layercomprise the same material, wherein the wedge dissectors comprise astrip-facing base surface directly adjacent the surface of each of thestrips, an unhoned radially outward facing surface having a lengthbetween a proximal edge of the unhoned radially outward facing surfaceand a distal edge of the unhoned radially outward facing surface anddefining a height of each wedge dissector, and lateral surfaces betweenthe strip-facing base surface and the unhoned radially outward facingsurface, wherein the unhoned radially outward facing surface has a firstwidth at the proximal edge, a second width smaller than the first widthbetween the proximal edge and the distal edge, and a third width at thedistal edge larger than the second width, wherein the expandable ballooncomprises a plurality of pleats extending from the outer surface andspaced apart from the plurality of strips, wherein the expandableballoon comprises a first reduced configuration in which the wedgedissectors of each strip lie between two adjacent pleats such that alongitudinal axis of each wedge dissector of each strip is in atangential non-perpendicular orientation with respect to the outersurface of the expandable balloon directly below each wedge dissector ofeach strip, and wherein the expandable balloon comprises a secondexpanded configuration wherein the longitudinal axis of each wedgedissector of each strip is in a perpendicular orientation with respectto the outer surface of the expandable balloon directly below each wedgedissector of each strip.
 42. The medical balloon catheter of claim 41,wherein the ramp of material slopes from the outer surface of theballoon to the lateral ends of each of the strips.
 43. The medicalballoon catheter of claim 41, wherein the ramp of material comprises anadhesive.
 44. The medical balloon catheter of claim 41, wherein eachstrip of the plurality of strips comprises a textured surface.
 45. Themedical balloon catheter of claim 41, further comprising a plurality oftabs on an inferior-facing surface of each of the plurality of stripsopposite the wedge dissectors.
 46. The medical balloon catheter of claim41, further comprising a plurality of reliefs on each of the pluralityof strips.
 47. The medical balloon catheter of claim 41, wherein thebase layer comprises a polymer.
 48. The medical balloon catheter ofclaim 41, wherein the bonding layer comprises a cyanoacrylate.